Am angry with the Cell C network

I bought a contact phone at Edgars Johannesburg city on the 8 of January, the same day I got the phone I got the wrong sim card ,I went back the following day they gave me the right sim card which is linked with my contract but still even if I put in the sim card it kept on saying emergency call only, then during that week of buying the phone , a consultant from cell c call me telling me my bill is now 900 yet I was not using the sim card, that's when I discovered that my sim card was used by some else , I went back to the store to complain ,the guy who helped me with the contract called the cell c people they told me a ***** has occurred I must go to the police station to get the affidavit and explain what happened , I did that then they said I must email it to them along with my contract I did that but they did not come back to me with the results, then I called them after some time I asked them to block the number which they did and they asked me to do a sim swap in order to get my number and my benefits , Then the guy called siphon called to perform the swim swap took all my details and said they will investgate and come back since March no one has bothered to come, am angry