I bought a Wizz "membership", promising a 10 US$ discount on all flights. Somehow I was not able to apply this membership to flights I bought after the first booking since it took them some time to internally activate it. The discount was only granted for the first two flight legs.So I bought a total 6 flight legs for 500 dollar total but based on my membership the charge should have only been 450 dollar.
I emailed them and they said that they overcharged me and asked for a 50 USD voucher since I wanted to buy extra check-in luggage anyway. They told me that my membership can not be applied to the selected flights. I emailed them screenshots, showing them that NOW I could apply the discount if I bought again but they did not accept. "Decision final."
I felt this was fraudulent, so I did a backcharge of all the charges. First the CC company settled with me, then with them, then after threatening legal action the CC voided all charges. I booked the flights with major airlines for basically the same price later (I am all major alliances gold status :-) ).
Was it worth it? It totally pissed me off. I even did not ask for money back but just for an in-house credit and I hate it when big companies try to play hardball with me. Yes, it was worth it.
On the other hand, a Chinese guy tried to sell me my own bike on a "street bicycle shop" that was stolen a few month before. I yelled at him a little bit and I gave him 100 RMB for repairs he did, bought a big lock-chain from him for another 100 RMB. These "street shops" guy are poor, they have no money. Yes, I could have called the police and fucked him over but it is easy to play hard ball against a poor guy. More fun to play hard ball against a company.
Airlines don't like admitting mistakes, and even less they like reimbursing people.
We tried the membership discount, and it worked as it should. (I bought it with the flight, so it applied instantly. Then I booked for a few more folks. But lately it doesn't make much sense, because it's only valid for one year, and who knows which budget airline will be the cheapest when we actually figure out when and where we want to go.)