MTN chariging me for a service that is not working

I have spoken to close to 20 people now trying to resolve this over a period of close to 4 months trying resolve a matter of the MTN made for home router that does was sold to me only to be told by MTN that it was not a suitable product for my home/area.

I was told to go to MTN store to get them to allocate a slot and it would work. The store said they could not assist and sent me back to the call Center.

The call center sent me from pillar to post until they told me to contact MTN Business for cancellation. Nothing came out of that as they still have not cancelled the contract and no ine has called me to give me a correct contract /divice. They continue to charge me every month.