Sentiment shared, but I doubt if there are any regulations to force the matter - I suspect that it is a matter of making the point firmly (but not rudely) that the situation is unacceptable. Getting a written statement of the circumstances from the Purser would be very helpful, and taking some digital photos to support you case might be very useful. Then wait to see what, if anything, happens.

I returned from AKL-BKK in F (A346) and was annoyed when the IFE (all classes) was shut-down some 40 mins prior to landing - I can accept 20 mins to go. I discussed the matter with the (new) crew who, whilst being very polite, could not explain. I asked for a feedback form/envelope filled it out noting my FFP number, status, class of travel and circumstances. I also asked to speak with the Purser and explained that I was submitting a feedback form so that service could be improved for subsequent travellers.

TG responded with a long letter of apology, a diary, and associated stuff. The real laugh was that the letter focussed on the fact that my seat malfunctioned (actually, it had worked perfectly), and that they had briefed maintenance staff etc etc. I couldn't be bothered to write back to them...

So, you might get a diary if you seat breaks down - anything more should be considered a bonus