Nok Air 

They offered me a refund of a flight that they canceled at short notice…having me to pay surcharges at another airline.
Months later, still have not received my money back

One of those flights where fellow passengers are praying,The plane has become a vomit comet and a round of applause erupts on landing.

Never fly with Nok air, plain and simple. In 2 days my flight was cancelled, re-scheduled, delayed, then changed completely. I tried to contact Nok customer service but was on hold for over 2 hours, no one ever responded to a single email I sent. Most unreliable and unresponsive airline company ever, I’m shocked they’re still in business.

You book and pay for a flight. A few days before they cancel the flight and you get 3 options: 1. fly to another destination the same day 2. fly to the same destination an other date 3. redeem your money on some other flight within a year.
All options are worthless if your plans depend on that flight and in the end you get to lose your money and more than that...
Sure it's "legal" but feels so much like a scam and, bottom line, the actual consequences are exactly the same as if you were scammed for real.
Do yourself a favour and book with Air Asia instead.

RIPOFF- at airport add 5000 baht/$160 for our two bags. Price went from about $120 for two; Phuket to Bangkok to $280. To late to make changes. I WILL NEVER use this airline and neither should you if you don't want to Ripped off!.

Sold ticket, and at next day they cancel flight, due to coronavirus, why you sell tickets in this case? Maybe you will sell my tickets to somebody else?

why i need your voucher, i need refund, for this “service”

calamiteux . service client nul , date modifiees sans mon avis et impossible de changer sans payer en cash .
si vous avez le choix , prenez tout mais pas ca . a fuir

Terrible airline. Avoid if you want to get where you're going anywhere near the stated time. Delayed for TWO DAYS.

Really nice young company with the wifi on the board and smiling staff.

Very simply put, a service's quality is much better understood not while it is being dispensed, but by how the company offering it reacts to any problem met.
In equally simple terms, NOK AIR is a company that reacts very poorly to mishaps.

SALES-POINTS
The company offers a variety of sales-points through out Bangkok: An online portal, a few scattered dedicated kiosks, some travel agencies and the ability to buy a ticket at any 7-11 shop.
As is the case with all budget airlines they sell a series of upgrades to every flight (such as meals, seat selection, extra-baggage space, etc).

Except that not all options are available at all sale-points. Buying at a 7-11 does not permit you to buy ANY of the upgrades. In my case, I was forced to pay roughly 50% extra of the total price of the ticket for not buying in advance the extra-luggage option that was never offered.

UNTRAINED GROUND STAFF
Explaining how all the above situation is the sole responsibility of the company and not the costumer to an annoyed already on edge staff is very hard when management places barely functional english speakers to take care of desks of an airline that flies internationally.

In any case, very quickly all combinations of passive-agressive rudeness took over the role of dialogue.

No solutions were ever offered and everyone else was blamed for the situation but the airline.
Humorously I was told to go complain to the 7-11 staff, disingenuously ignoring that 7-11 is just a place offered to Nok Air to sell their services, not the service itself. And the obvious fact that 7-11 didn't create the software with which Nok Air sells its tickets there.
Deceivingly I was told to go complain to the office in charge, which in reality was only a sales office inside the airport (that reasonably had no authority nor the capacity to deal with this particular problem).
I was blamed for not having the forsight to plan my trip better.
I was told that I should buy my ticket from the online portal, failing to see that ALL sale-points MUST offer all available features all the time.

In the end all I was able to do was fill a "Suggestions" form and trust that they would care to read what I had to say about their inadequacies.

RESULTS
For the price I ended up paying I could've flown using one of Thai Airways smaller lines, Thai Smile, for considerably less of what I invested and much much less of the resulting bad mood.
Why 2-stars then? Well, they can still fly a plane, the installations are clean and they are mostly almost on time. Mostly. But don't take this as any kind of recommendation.

Nok Air is the only airline I’ve ever flown that charges you a baggage fee PER CONNECTING FLIGHT. Thus, in addition to paying its already exorbitant baggage fees, I had to pay it twice, because I had a layover in Bangkok. None of this is advertised or disclosed that I saw. On top of this, the customer service was horrible because the agents are unable to explain the baggage policies either because they couldn’t speak English well enough or they just didn’t understand the airline’s baggage policy.

Bottom line: You may think you’re saving money flying with NokAir, but if you are flying with any bags, save your time and money and fly a different airline.

Would definitely recommend. Took a few Nok Air flights within Thailand and had no problems whatsoever.

I actually find Nok Air a perfectly fine budget airline in Asia. Flown with them a few times and they're absolutely fine. No problems.

Rude and aggressive staff very old aircraft and no safety no comfortable seat even on business class.
Most complained airline company in the world, yes its cheap but doesnt deserve $1
There is no way to that You can not complain or contact with someone who is in charge most of the staff doesnt speak english...
Never book again!!!

Bonne compagnie, à l'heure et bien efficace! Des bouteilles d'eau ont été offertes pendant le vol ce qui est rarement le cas sur les lowcoast.

Excellente compagnie
Toujours à l'heure très bonne expérience sur les 8 dernières années.

Ich war schon zweimal mit Nok Air unterwegs (Bangkok - Hat Yai 2016 und Bangkok - Chiang Mai 2017) und habe nur gute Erfarungen mit dieser Airline. Abwicklung und Kundenservice sehr gut, ein Super Preis-Leistungsverhältnis.