Standard Bank no response to any requests for info on alleged changes to debit orders.

After decades of amazing service with Standard bank with accounts, loans, a bond... I purchased a vehicle a couple of months ago through them. A month or so ago I received an sms saying there was a change to the car debit. I phoned the bank to see what this was and was told that in December they were going to take the instalment on the 16th instead of month end. I said that was not possible please do not do so. They said an sms would be issued where I could opt to agree or keep the existing date. No such sms has come. I sent 2 emails to standard bank asking about this and to ensure it is not taken on 16th, I was told to contact vehicle finance. I sent them two emails and have yet to have any response. Really bad service and I certainly hope someone heeded my emails anyway and there is no change to my debit order date as I do NOT get paid early in December and even if I did, how is it up to the bank to decide they want to debit early. Very disapointed.