Disgusting lack of customer service

Discovery takes 2-3 days to respond to a simple request and then does not even bother to respond to what I have requested. After 2 weeks of trying to get feedback from Discovery Card on trying to identify the easiest way to change my address details on their system, they have now threatened me that they are going to close my account. There is no wonder people do not even bother to update their details because Discovery Card makes this impossible. To apply for a new card, you merely have to show your original copy of proof of address