Bloody hell, yes! Make an official complaint! This is rather serious I'd say. I suspect it'll be hard to prove you didn't just crush some glass up and put it in there yourself to try and get some compensation though In hindsight, I've have taken my own photos of the glass, the glass it was found in and made some detailed notes about the chain of events (i.e. you'd just got onboard, it'd be hard to crush up some glass...) and crew names (for corroboration of details), etc.

I'd me mighty worried if I found this in my food/drink...in your case you were actually injured too. I would say you're entitled to at the very least a large chunk of miles...

I would write a factual letter with as much detail on the times, circumstances, etc. as you can recall. I'd imagine the crew reported it too so there should be records somewhere in BA too.

Not a nice experience, sorry to hear this happened to you

Phil