I took a data contract online and it was quick and easy

I took a data contract online and it was quick and easy. When the 2 years was done, I canceled the contract. They tried to debit my account. When I logged a query, the contract was still showing as active....more than a month later. I cannot get hold of an actual person to speak to about this. I eventually resorted to Facebook Messenger, but I have to keep explaining my story over and over again. According to them, my complaint has been escalated 3 times. I was told someone would call me. We'll, it's a month later and still no call. Now they are threatening to hand me over and STOP SERVICE IN 1 DAY....what service???? I canceled this contract. Shocking shocking none existant service.