Error i2501 issue

My account has got an error code i2501 roughly a month ago. This prevents me from purchasing any service, including adding subscription time. I've contacted the customer service via email or chat many times and they always tell me "my account is still under investigation". The latest response is "since you can still access your account now, come back after your subscription expires and see if you still have that error", which I don't think as a viable solution (if they cannot fix this problem when I still have my subscription on, it is not likely they will suddenly decide to fix it after it expire).

I hope posting this thread will help the investigation team put more attention on my case and see if anyone else is getting the same problem.