FNB pathetic service

How is it possible that after sitting in a queue for 35 minutes, I eventually get to the teller only to be told she does not have any R10 notes. I needed to exchange R100 notes for R10 notes needed for change in the shop. When I queried how it is possible that a branch does not have R10 notes, she told me those she was issued with for the day are finished. So I told her to get some more, surely there must be more in a safe. She phoned someone and then told me that her manager says I must go to another branch. Seems a good time to me to go to another bank altogether