if you are using paypal, cancel it from the paypal site and put in a dispute. If you are paying by credit card call your bank and tell them you have been falsely charged.
Tell them you have tried cancelling and calling their phone support but they billed you anyway against your wishes.
This is outright theft plain and simple.
I honestly can't see credit card companies or paypal doing anything about it, unless he has a recording of the phone conversation as proof he asked them not to bill him anymore.