Gross Incompetence by staff at Chatsworth Branch

Went to Standard bank Chatsworth on 09/05/15, drew a bank cheque for R5000 for an auction. On 13/05/15 deposited this cheque into my account as I didn't use it at the auction. The teller helped me fill in the deposit slip. I had to put the cheque on special clearance. Today, 15/05/15 at 3pm I received an SMS informing me that the cheque was unpaid upon calling the call centre, I was told that the cheque was flagged and other excuses. I found this very strange since this was a bank cheque made to an auctioneer, unused and then cancelled by me so I expected my R5000 back into my account. Instead the cheque was unpaid and the credit balance in my account was used to pay this R5000 with my account now being overdrawn. My understanding of a bank cheque drawn from monies from my account, cancelled and then deposited back into my account does not result in the bank cheque being unpaid and the credit balance being used. My question is: WHERE IS MY 5K AND THE OTHER MONIES TAKEN FROM ACCOUNT. I also have a debit order for today that will now be unpaid because of the negligence by *********** staff at this branch! My prestige account is also brand new and I find this error unacceptable