If you can avoid them...please do!

I canceled my account via email on 11th December, emailed the client service email address. It's March, I'm still getting debited. I understand there is a 20 day notice period and my cancelation request was submitted 11 December 2020 so I shouldn't be paying them anything. I try calling the client service extension they don't answer phones. But the accounts department calls me everyday about outstanding fees because I keep reversing their ******* debit orders. The very rude accounts call Centre agents call at the most random times even on a Sunday. I'm exhausted with having to reverse their debit orders. I've spoken to more than 11 agents from the accounts department and still it's not resolved. On Friday I got a call at 5.56pm after work hours from an agent and explained to him the same story- his response was that the accounts department and the client service department are separate departments so my cancelation is an issue for the client service department. So I wonder am I supposed to act as a mediator and assist with communication between 2 departments in one company as a client???? Is the company so disorganized that 2 departments cannot communicate to each other and a customer has to suffer for it? It costs Me money each time I have to reverse these unauthorized debit orders. My bank charges me fees! And I use airtime to do this. And I have been using airtime trying to reach your client services telephone number which puts you on an automated voice machine and never gets answered. Its been a horrible experience! Worst customer experience ever!