Not much difference in most banks.
Student or Learner
What do you think is the difference between "bank teller" and "bank clerk"?
"Can I borrow one dollar?" a little girl asked a bank clerk. The clerk replied, "Do you have anything in your house worth one dollar?" "No, I don't. But my sister has high fever. She needs to see a doctor immediately. Please help us." "If you don't have anything, we can't lend you money. Sorry."
In the UK, 'tellers' are more commonly called 'cashiers'. Not all clerks work as cashiers, who are specially trained.
The dialogue in the original post is so ludicrous and unlikely that I don't think the difference (if any) between "bank teller" and "bank clerk" is going to make any difference!
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.