Change payment method

I have been trying to remove my card details off of the payment options and I am unable to do so without other card details. They are keeping me hostage. I’ve phoned in a million times sent a few emails and nothing is happening. I want to choose another payment method. And I can’t because Rain is keeping me hostage. The worst service under the sun. I am going to report this as ***** through my bank ad I have requested this payment options to be removed a million times.