I find it a bit strange that the purser on the flight did not immediately deal with the compensation.
On all my previous occurrences with issues with AVOD or seat functioning - and after unsuccessful attempts to repair - the purser has come by my seat by the end of the flight with their iPad and handled a claims form there and then. Typically you get the choice between a couple of 1000 FF miles, a cash refund (limited) or a voucher (typically worth more than the cash). I found it to always work like a breeze : handled while still in the air and is then automatically processed after the flight (I presume when the pursers iPad connects to the central system).
It seems that in this case either the purser was not informed of the situation by the FA or the OP (or didn't care enough).