When the Contract Ends, They Refuse to Cancel

I cancelled the contract in February and sent emails to ***, but money is still being deducted from my account. I also went in to RICA the number so it could be converted to prepaid. Now my number is not working at all — I cannot make or receive calls. When I call for assistance, I am told the number is still on contract, but when I go to the contract department, I am told it is prepaid. I am being sent from one place to another, and no one is helping me resolve the issue