Bad service by cashier

I was at a till to make a deposit, I stood on a queue when I reach the front a lady said I must go and make a deposit on another till because she gonna be going to lunch soon and she was not allowed to leave a till with too much cash, so I must go and join another till. What kind of nonsense is that?

Unfortunately I didnt get the name of the cashier but she was light skinned young lady, I can poin her if I can go back to that store. I was so annoyed