No communication from a communication company

I closed my business over a year ago and on 18th March 2022 i closed my business account with Telkom. I sent them all the correct correspondence and filled in all the relevant forms, which they acknowledged receiving. However they still constantly draw from my account via debit order and each month I vave to instruct the bank to reverse the transaction. Each month the amount changes. I have phoned and written countless times. I have been into a Telkom store four times. Each time I get told someone will contact me. This has never happened. In frustration I even closed my home Telkom fibre and when I had a call from that department asking me why and I told them, all they did was offer me a discount on my fibre package. I told them that all i wanted was for them to fix my landline problem and then i would happily stay with Telkom fibre. Obviously the line went dead. I'm now with Vumatell.