MTN never ending contract - you can sign up but never sign out !!!! please hold

I am trying to cancel my data contract that has lapsed ***, having called call center and given my details I was told to hold on for retentions which took almost 40 min, here again having to submit all my details I asked to terminate my contract and keep my number as pre-paid, again holding on was told that there was an error that they could not resolve on their side as it was a smart home package, they transferred me to 3rd party company and holding on again was helped by technical department telling they cant hep and was transferred to accounts who told me I do not even reflect on their system. I called MTN again and requested to be transferred to call center manager as I wasted almost an hour without any progress. No systems are down they will take my details and call me back . So bottom-line MTN has me in contract that served its time that I am now unable to get out of as no one at MTN knows how to cancel it !!! How on earth is this possible. Whatever you do do not get superfast WIFI router for your home as service support is super slow to the point of not existing. Install Fibre