Unauthorized Debit

I want to move my account from Standard bank, last month an unauthorized debit order bounced back because there were no funds available as a result my account was on a -ve balance and I had to pay R115 for that bounced debit order. Today I received a call from Standard bank notifying me of a -ve balance. I went to the ATM and again some unauthorized debit order bounced back. I'm now owing R115 which must be paid by me, secondly I don't have debit orders that are running on the 15th of the month or so because I'm getting paid on the 25th. I'm left with no option but to move my account from Standard bank into another banking company unless they stop these unauthorized debit orders and return my 2 x R115.