It sounds like an extremely informal conversation, to the extent where "so much when" and "what makes you angry?" don't really make sense to me here.
Generally you would hear a conversation more like this:
1. So yes, "got", means "have" in this sentence. It means that, the customers don't have the right change needed to buy the coffee and present the shopkeeper with a larger currency note, which in Britain would be something like a ten, or twenty, pound note. This means that the shopkeeper will soon run out of change in their till and then will either, have to go to the bank, or close the shop if they can't get any more change. That's why small businesses hate it.
2. Yes, you spotted this. It is a contracted form where speakers know the meaning of what is being said, even when words needed in more formal versions of English are left off. Several variants could be used to correct this. I have shown the simplest.
Where did you hear the conversation?