Unwillingness to admit error and correct it

I have been a Standard Bank customer for nearly 10 years now. I have had multiple accounts, a credit card, home loan and more with them. I am even a prestige banker with them for the last 2 years. I app**** for a further bond in May and got a call to inform me it was approved on the 29th of that month. On the 1st of June the appointed attorneys called me to say they are waiting for the documents from home loans to finalise the paperwork for signature. On the 2nd I got a call from the attorneys to state that the bank made an error on the documents adding the approved amount to the existing bond and not adjusting the total balance as per the application. Both the attorneys and myself reported the error to home loans that day to correct it, but they stated to us that amendments take 5 working days. I told them this is ridiculous as we are not requesting a change, but informing them of their own mistake. It has now been nearly 2 full weeks and we are still waiting for them to send the corrected documents to the attorneys. I have even logged an official complaint to the Resolution Centre only to be told 8 working days turnaround time. Really frustrated now.