Welcome to Flyertalk and welcome to the BA forum Pelu, it's good to see you here and I hope you will be able to be a regular participant here.

I can't really see how this happened either, unless you moved seat or some such. I presume this was flying to London. Given the recent operational difficulties I imagine the risk of being low on food greater at the moment, but I think it's unlikely you were the last one to book that flight. My suspicion is someone accepted an upgrade and it was wrongly marked against your name.

What should have happened is that senior cabin crew member should have enabled you to have £10 worth of food from the buy on board menu. If not then the SCCM should have made an Avios offer from their iPad. If s/he didn't do so then my understanding is that if you pay for that anyway using Avios then that would be refunded plus some further Avios if you only had 1 or 2 items. At this point you should send in a brief complaint to Customer Relations via BAEC using the Contact Us bit at the foot of the page, and you should get about 4k Avios eventually (up to 3 weeks lead time currently).