after 2years of no contact I have a R9 325 bill

I have been a loyal cell c client since 2002, and took 2 additional contracts in 2008, in Feb 2013 I received a call saying that my account bill has run upto R4 733.92, my avverage bill for the 2 Contracts never exceeded R400 per month, I advised that I did not use the numbers in the past month and there was no way this could have happened, I discovered that the one of the phones were ****** the previous week, by builders at my home, I immediately stoped the number, called Cell C for assistance, I reported the case at the police Station, and went to the Cell Shop in Tygervalley, wanting to know how it was possible to run up a bill that quickly, in the space of a week, they were not able to explain, it was not phone calls,seemed like subcriptions, I was given a number which I called and was incorrect, I asked them to provided feedback and to explain, which never occured, further I asked to have the account closed, and to make an arrangement, and advised that the would be closed, there was no further follow-up, now after some investigating,I have a bill, I have been trying to make arrangement, and been dealling with a Karabo at late recoveries, and have not had any feedback,so poor