Sub standard bank Home loans

I had paid R1150.000 into my Standard home loan,THis should have brought my installment down from R18150 to R5850 Per month,month end came and they deducted the full amount,I then contacted them and it was agreed that the balance which was about R12K+was going to be refunded, However they put back into my account the whole amount of R1150.000,By then i was back at work in Uganda.I contacted them wanting to know how this could happen as for such a huge amount to be paid back requires quite a few high profile signatures,I was promised it would be rectified,A MR Mhlanga phoned me and assured me that he will debit my account again.So on 22 december my account was debited and funds showed in my homeloan but nothing deducted from my side (Nedbank),I tried contacting Mhlanga regarding this.So today i get an email from Standard bank saying money was returned to my bank,I then got a call from Mhlanga trying to once again sort out there mess to no avail, So i sent an email saing that because of there incompetence and costing me nearly R24000 loss in revenue earning,that they should stick to the bond deduction of R5874 as it was their mistake and i cannot be penilized for their gross incompetence,20 Minutes later i get an email with attachement saying that they accept my payment arrangement and that i will then be in arrears and i should pay the balance as soon as i can....REALLY!!!!! Standard bank has really gone to a new state oh high incompetency!! I do intend to take this further as now my impeccable credit record might be tarnished by these baffoons!!!