Taking money thats not due to you!

Good morning. Today my autopage debit order went off. Imagine my shock when it was TWO HUNDRED more than it was supposed to be. I normally get debited R424.50, today it was R624.50. I was shocked as I have a top up contract, everything cuts off when it runs out and I cannot even if I wanted to go over that amount. I called in to the branch (Galleria Durban) and spoke to a lady named Subashnee. She checked my account and saw that there was a mistake in the billing and that you people did indeed over debit me by R200. She said she will contact head office and notify you people of the mistake your'll made and that it would take 7-14 days! When I asked her why and when I can expect feedback she didnt seem to have any answers for me and was extremely rude and short with me! I do not expect such pathetic service from a company who I have had my contract with for over 10 years, despite bad service repeatedly. I intend on NEVER renewing my contract again. Furthermore this is NOT my fault. It is AUTOPAGE fault! Therefore why should I be the one who has to wait so long for MY MONEY to come back to me. YOU took the money, i want you to return my money back into my account as soon as possible!