System Issue and now cannot upgrade.

<br> My mother has had a contract with MTN for the last 15 years. My number is on my moms contract. We have always upgraded with no hassles. This year my upgrade was due 01.02.2015. I have since been to MTN Eastgate 4 times, each time being there for more than 2 hours and they just cannot process the upgrade saying that for some reason the system doesnt allow them to go into my number, therefore they cannot do the upgrade. They have even dealt with head office and asked for assistance which they did not get either. Same story from head office, they cannot get into my number and have to log a request. This has been done twice and till now no one has resolved this.The service being received in pathetic. All i want to do is my upgrade and i cant due to MTN's stupid system and now myself as the customer is very Inconvenienced. I please need answers and asap and have this resolved before the end of the week. Otherwise i will be terminating this contract and go to another provider and i will close my own personal account that i have with MTN as well.<br>