Disgusting Service

About a month and half back I went into the Cell C Trade Route Branch and enquired about a contract I had with them. The consultant (Shuaib) advised that the contract had 0 months left. I also enquired if I could port the number and was advised yes as there was 0 months left on the contract. I ported the number to Vodacom, and am receiving my benefits from Vodacom, however I am still been billed from Cell C. When I enquired with 084 140 they advised that the contract expires on the 15/12/2015. I contacted Naasir, manager at Cell C Trade Route and explained the above, he had a very bad attitude, refused to assist and attempt to sort the problem out. All that he could tell me is that the system is telling him when the contract expires. When he called me back with feedback advised that there is nothing he can do as I am not able to receive benefits from 2 service providers, so in other words I have to pay for something I am not receiving any benefits for. Is this not *****ing from Customers? I refuse to accept that I should be paying for something and not receive any benefits. Why wasn't I informed by cell c porting dept that this was not possible. Surely there are checks in place.