Should I take my business elsewhere?

In March 2015 I claimed for temporary disability. My card were blocked during that time. I submitted documents when I submitted a complain regarding my blocked card. I mentioned in my letter that I want to close my account. In response, RCS decided to send me a settlement letter and never even explained why my card was not unblocked. I decided I wasn't closing my account and I went to enquire at your Southgate store and to my surprise the card was still blocked. I want you in writing to say that I can no longer be your customer and that you do not want my business! I feel that RCS \took offence"that I wanted to cancel my card and decided they will not have me as a customer. If that is the case"