4 months now still struggling to cancel my contract

In May 2017 I received a call from Summer Mobile on behalf of mtn offering me an upgrade, which I gladly accepted, I was promised a device that will be delivered within 7 working days for my upgrade, this never happened....

Towards the end of June, I once again got a call from Summer mobile apologising that the devise was never delivered as they were out of stock and once again asked me if I still want to go ahead with the upgrade, indeed I agreed, 1st week of July I got an sms from mtn that my upgrade was successfully loaded yet no device was delivered nor was there any paperwork that I signed proving that I accepted the upgrade.

I waited until end of July for the device but it was never delivered, since then, to date i have called both MTN and Summer mobile trying to reverse and cancel this upgrade but all I received is empty promises from both parties.

I have asked several times that this contract be rather cancelled and my number be moved to prepaid and to date nothing...

23rd October 2017 I called mtn once again (ref: ********** 44) and actually sent an email to the mtn retentions department (ref: ********** 3), I was promised I'd get feedback after 2 working days, to date (31 October 2017) I haven't heard anything from them... 14:50 today I called MTN to follow up, spoke to a consultant who said they are transferring me to the retentions department, it's been 25 minutes now I'm still holding for someone at the retention department to answer the phone, even sent an email to the retentions department while waiting (ref: ********** 5).

I want you to just cancelled my contract or I will reverse the next debit order if this is not done and we shall meet in court if need be.