MTN Sandton ***** work

I did an upgrade on my data contract on 05.02 and I am told that the Sales person who did the deal captured it incorrectly. I have gone to the store already 3 times till to date to try get this sorted out. I have tried other MTN stores and Customer Call Centre but unfortunately , only the store that did the error can rectify it. I am now seating with a bill that I am not prepared to pay as I didn’t sign up for this.