Bad experience at American Express

I had the worst encounter at American express, l reckon he is a new employee because l have been coming to the same American express doing the same transactions. But today l meet this new employee l am polite enough as a customer but he starts shouting at everything he thought l wrote down wrong. He enters my information incorrectly and dismisses me. I am patient enough to receive help on the next counter. To say the least l am disappointed at the unnecessary shouting and bad attitude l got from the employee.