Refusal to end contractual agreement by MTN

In December 2022 I attempted to cancel my last contract with MTN and they kept offering upgrades and these upgrades did not materialise due to a block in my profile. MTN the initiated a new bill from R 150.00 to R 350.00 this after indicating to them no interest in continuing with the contract. MTN then blocked all other numbers that I had already converted to prepaid and no outlet of MTN can help as they only help if I pay for services that I am not recieving from them. The two block numbers we have using for years and most of our personal business was conducted through them.