CANNOT RECEIVE INCOMING CALLS - ***

I took out a contract MINUTE_50 at the Alberton City Branch of Mtn on 17/08/15. I took the simcard home and inserted it in my Samsung Phone only to discover that everything worked except the incoming calls. I have phoned all the numbers pertaining to problems 808 + 1555 the Technical department. My partner has been to the Alberton Branch and they have done a sim swap, to no avail. He has now been back and forth 5 times and it still does not work. We have a list of reference numbers now. A person by the name of Mpho, phoned my on Friday 28th August while on another phone with my partner, and promised that it would be working by close of business on Friday. NEVER HAPPENED! Friday night we phoned again and this time spoke to Kenny in the Technical department, who said we should cancel the contract and start a new one with a new number. When my partner went back today 31/08/15, the manager Mr. Humbalani Nedane refused to cancel the contract and gave him another code to use, which DOES NOT WORK. The invoice number is ***2. We have now spent 19 hours collectively and about R200 petrol to solve this problem. I feel this is VERY POOR SERVICE AND WANT TO CANCEL THE CONTRACT!