Bad Service

I cancelled my contract on 15 July 2015 after a dispute with Cell C. The consultant gave me a settlement amount of R349 to pay afeter which my account will be cancelled within 48hours ,which I done. I received my notification of the cancellation within 48hours. Yesterday almost 3months later I received a phone call out of the blue that I still owe Cell C R350.00 ,the consultant with much attitude tell me I was billed before the time which I was never informed of. I never received a sms or call from Cell C for almost 3 months . I want this matter sorted out and my account cleared. I will not be held liable for someone`s incompetency. Please listen to the recording of the 13 July 2015 .