I had the same experience on SIN-LHR one night on a 747 in WTP. The lights just wouldn't go off. Probably the worst part was getting up to go to the bathroom and having to walk through a pitch black Y cabin with everyone fast asleep.

I emailed and received £30 in service recovery which seemed a paltry amount - I would have much rather had Avios, but it seems they can't cope with people who have an Exec Club account but credit to another program for any reason.