Account blocked without proper notice

How on earth can a bank just block your account and leave you with egg in your face at tills and petrol pumps. Their answer is just that you should have got a notification to fica. Well my daughter did not see a notification, neither did my son a few months ago. I hope you realize that most machines now a days just give a message 'decline' which leave everybody behind you in the queue to believe you do not have money to pay. Is it OK to embarrass your clients like that? Not in my books... Phone calls can be made to sell all sorts of stuff, but not to fica clients??? Well don't be surprise if you loose a lot of clients due to this sort of customer service.