Misleading Account Cancellation

I made an online application in August with Computech Credit Services. It was not long before I released that the service was not good and I requested the service to be canceled. Last month money was deducted from my bank account. When I called the company they said it’s not their company that deducted the payment. I have now received a legal notice And they demand R1300 x2 for two accounts. I was informed via telephone and email that the account was canceled. Fed up!