Merchant Services inadequacy to follow a simple request

We have had our merchant machine with Nedbank for about 9 years now and despite following "procedure" to get an instruction through to them, they don't seem to give a hoot thus me resorting to HelloPeter - it seems like the only way to get the message through and to have someone actually follow through! On 12 Dec I sent through a request to change the banking details immediately and an automated message was returned stating that it would take 24 to 48 hours for this to be attended to. Hearing zero for a week I emailed them again and I was told that this would be attended to - again ZERO! There is a specific reason why the instruction was sent through yet Nedbank thinks it is great fun to muck the client around no matter why they needed the change over. Now when can we expect this to be done? It is already too late to change over this month's debit orders, and obviously FAR too late for this month's transactions to reflect in the new account... so when are you actually going to action our request? Next year perhaps? Or the year thereafter? At this rate I am seriously considering leaving Nedbank Merchant Services and going to a bank who actually does their work! I have had several problems with NMS over the years but this is starting to really irritate me to the breaking point! Is it SO hard to change banking details? PS. We are going to be purchasing a car in March (was supposed to be early, but now thanks to your inadequacies will have to be late) thus needing the transactions to reflect on the bank statements from a particular date in December 2019! Thanks for not doing your job - it shows me which bank to avoid!