We both, however, think they are taking the mick. Just a bit.
Aye, right enough. Thing is you'll never get Peroni to admit that what you sent them was a piece of glass. Mould is probably what every single foreign body is (whether it is or not) this is for several good reasons.
1. they don't know that you're not a journalist, and tomorrow "Peroni beer in lethal glass shocker" isn't going to be splashed all over the front page of the Sun
2. they have no way of telling whether what you sent them and the story you've told them are in any way connected (I'm not doubting the veracity of your story), but I'll bet they get all sorts of chancers
3. Admitting that sort of foreign object in a bottle of their product would open them up to the possibility of litigation. Hence the standard first line defence of: Mould.
4. there's more, but I'm bored.
If it bothers you get a solicitor to fire off a strongly worded letter. However Peroni can afford a better lawyer. You know, they know, move on. Bet you 50p some production manager is getting an extra arsehole ripped