Poor service!

I am on a flexi contract with MTN. I called MTN wanting to be assisted with a change of debit date. I was advised that I can do the change through self-service on the APP. After realising that such a provision does not provide such a provision. In the process of trying to navigate the system, I mistakenly clicked on the wrong tab which upgraded my package. I immediately made the consultant aware and requested to be assisted with making an amendment and return to my initial package. The consulted referred me back to the App, which again does not allow for an amendment to be done, It only shows you a message that 'your request was received. On two occasions, I was advised that I would get a call from another consultant to assist with the process, but I have since not received any correspondence from anyone from MTN. I am concerned that I will now be billed incorrectly due to the mistakenly opted package upgrade. Also, the date of debit will remain the same and not changed to the one that I want. Can anyone from MTN assist with this simple request.