Wrong amount of money credited after deposit

I deposited R600 into my account the teller made a mistake and wrote R400 on the deposit slip which she filled in. When I realised what happened I returned to the bank she and another consultant told me that the money would be counted and then it would be credited into my account. I called the head office and I was told I would be called back and I was not. This inconvenienced me because I had planned to use the money for my varsity books.