Very poor service from MTN South Africa

I have been trying to cancel a contract with MTN since October 2021. Eventually 2 months ago I needed to purchase a new cellphone on a new contract and again attempted to cancel the existing contract. A month ago, after many phone calls to MTN the contract was cancelled but I had to wait the month for this to come into effect. Today, I received an SMS message from MTN to say that the contract has now been changed to prepaid. I am trying to apply for a new contract with Vodacom and need to port my number from MTN to Vodacom but am still unable to do so even though MTN acknowledges that my number is now on prepaid. The amount of phone calls, promises to phone back and promises of action are too numerous to mention. I am incredibly frustrated and feel that I am being held ransom by MTN and completely powerless to do anything. I would definitely not recommend MTN to anyone ever again. Their service is absolutely appalling and clearly they just don't actually care.