Service charge error ABSA System listed bad payer

I have app**** for a bond through ABSA, which was granted, I have tried to change the bond conditions and went through a broker who has come back to say I have now been listed as a bad payer through ABSA and FNB because R17.21 was not taken off my account for the vehicle I purchased through ABSA on 24 July 2014. Therefore I cannot get a bond with ABSA or FNB. On phoning and querying the lady stated that it was a system error that they hadn't deducted the amount when taking the first instalment and I need to phone the collections department to have it removed. I have been trying for 2 weeks to get hold of the so called collections department, either the phone rings or it says line busy. please can you have this sorted asap as I would like to have my house bond through ABSA who I have bank with since 2001 please can I have this error rectified immediately. Secondly you need to sort our your number for the collections department as it doesn't work or at least an email or fax number.