Originally Posted by bhomburg

Seeing that Qatar customer service doesn't even bother to communicate with you any more, the advice you've been given when you posted this originally in the Information desk forum to file a chargeback for the seat fees (you pad for a premium seat and didn't get one) is your best recourse. The economy cabin on the upper deck is usually only accessible for hefty fees (or if you have oneworld status), and you didn't get to travel in what you paid for.
Qatar will not voluntarily pay you back anything for inoperable IFE - if you want financial compensation for that you will need to drag them to court. What they do is throw a few Avios your way, but that's the end of it.
The time to escalate this should have been right at boarding time. You should have gotten the gate agent involved.