Unsolicited overdraft

I received a call from you call center requesting me to visit your branch without any further explanation. I took time of work only to be told that I owe ABSA R5200. I don't have a overdraft facility on my account. as per you consultant's feedback( Tumi Mohlaba at the Rosslyn Branch) Absa, being so generous, gave me a "floor Limit"of R6000 meaning my account could go in to the negative by R6000 and as soon as money comes in to my account, it gets deducted. Shouldn't my card decline when there are no funds available? I tried transferring R5000 on the 23rd March and it didn't go through. I tried for the second time and I got a notification of the transfer. now that i think about it, that's the 5000 that owe ABSA please fix your system