unable to reach call centre

We are trying to cancel one of our MTN lines since December 2014. The stores informs us we have to dial 808 but when dialing this number, the IVR comes up and after a while a beep and the line is disconnected. We went to 2 stores and they told us unfortunately that is the only way to cancel a line. One of them phoned on their dealer phone and after holding on for more than 60 minutes we could not stay any longer and left the store. Again they told us the only way to cancel a line it to phone 808, but they are unreachable. it is now 2 months in which the debit order goes on but there is no way to cancel this. We have 4 lines but at this trend we will definitely port it to their competitors. There is an absolute lack of service and no customer services in this regards. Our acc number is A*** and line to be cancelled is ***. This data line is not in use any more and we want a full re-embur*****t for the months not used. It is not the customers' problem that they have pathetic service and unreachable. The keep on increasing their footpring in Africa but back home they cannot even get their call centres to answer a phone call - no wonder they keep on loosing custom