MTN Incompetence

I took out a data contract Mid December 2020, I was told it was a top up contract, so when the data ran out I tried to top up and couldn't, I was told I had to phone in each time, the wifi modem that they supp**** was faulty and that was returned. I then sent an email to customer care to cancel the contract on the 31 December 2020, I let the debit order go through December and January to cover the cancellation fees, I have sent through several emails and made numerous phone calls and have received reference numbers, yet account is still not cancelled - I eventually called Mondo in Feb/March and was told it was cancelled - this morning I received an sms from Mondo asking me for payment and that the contract is still in force. I have checked the sim card mid January and no data on the sim - I will never with this company again