glitch with payment completion in gem shop

I have 2 case numbers and numerous contacts with the tech support people. When I try to complete the transaction I get an error message that says there is a problem with my account.

After four weeks, I haven't received any help. I have done everything that tech support has suggested, and nothing has changed. They escalate it to a support team, and I never hear back. Apparently, after 23 years on this platform, I do not even deserve the common answer and solution to this problem. Funny thing, and they know this, on the first of the month, I am able to complete a single purchase at each dollar level. After one purchase, the error message reappears. I am instructed to post to this forum in hopes that a manager or someone who has the skills to troubleshoot the software will finally see this and actually help me. I guess they don't want my money.