After having read your post very carefully, I have to agree that although this man didn't have to be quite so heavy handed, and could have perhaps said 'Excuse me I'm in a rush, do you mind if I uses the machine first.' It does indeed seem that you weren't actually using the machine but had all your belongings; cheque book, card, papers and purse resting on the machine and were using your phone, so to anyone else it may have seemed like you weren't using the machine at all, which can be extremely irritating to someone in a rush who has come into the back to find that only one till is open, and the bank is full of people! To sum up, perhaps he should think about the way he speaks to people, and you should think about not obstructing the machine before you are actually ready to use it?