The code signing certificate has already been used

Background of the issue: My previous Partner Center account was disabled. After contacting the Microsoft staff, the account was not restored successfully. Microsoft advised me to apply for a new account.

My current situation: I have used the information of my company to reapply for a new account, and it can be logged in normally. The status of the new account is "Authorized". However, when I tried to submit the certificate, the system prompted "The code signing certificate you used to sign the file has already been used or the certificate name has already been used by a different seller. Please use a different certificate." I wanted to submit an issue in the Partner Center to solve this problem, but in "Help + Support", I couldn't submit the issue because there was no workspace to choose.

My expectation: To have a way to submit an issue and communicate with the relevant personnel of Partner Center to resolve the problem with my certificate.

I don't want to purchase a new certificate because the current one is still valid for quite a long time. And in fact, the Partner Center indicated that the certificate was being used because it was occupied by our old account that could not be restored and accessed.