Paying for a service that I'm not able to benefit from

I've been an mtn customer for about 20 years and never has it been necessary for me to Rica my sim cards myself. I was always under the impression that mtn does it. I only found out recently that it's done by the courier company. I received my new contract router on the 8th. I have since not been able to use it. Firstly my sim hasn't been rica'd. I tried phoning the courier company and could not get hold of them. I waited and phoned mtn again. I then decided to Rica it myself. Did that and still no connection. I phoned mtn again and they told me that they will escalate it to the it department. I never got a call back. I phoned again and the consultant told me that I need to set up my apn. I did that and it connected for one day. I phoned mtn again and they transferred me to the tecnical department. I couldn't get through as they were closed at 9:30am on the 24 of December. I phoned again and when the consultant told me that she will escalate it I lost it as there has been escalations to billing and the it department and I have not received one call back from mtn. The other issue I have is with the payment agreement. It was agreed that I would only start paying at the end of January. When I mentioned that they had no record of that agreement. The consultant told me that I am liable for the payment although the error is on their side. Mtn has already sent me a bill for the end of December yet I have only been able to use the internet for one day. This is a major inconvenience me for as I have not been able to do any work from home and that puts me in a bad position with my company. Mtn what is going on. Does your consultants need more training or do you need new management. Clearly it's not being managed properly. I need urgent feedback.