BAD SERVICE/ FONE CHOICE

I've had a 26 months cellphone contract with the above mentioned business which ended on the 25th January 2022. On February 2022 they debited out of my account stating that my account is in arrears . I then gave them the proof out of my bank statement showing that I have infact paid for the arrears. They are not having it instead they keep deducting from my account even though I have proof. My and the endless calls are draining. I have emails to proof my account/contract with them has ended.