I would try sending an email to Microsoft CEO, Satya Nadella at:
Use brief details from your first post in this thread along with the error message screenshot.
Possible email shown below.
Subject Line: Reinstate Partner Center Program Account for my Software Developer Business
Dear Satya Nadella,
I need someone from your staff's to help me get my Partner Center program account reinstated for my Windows developer business.
I attempted to login to my Partner Center account and I received the following error message.
insert your screenshot of error here
I did not receive from Microsoft any email notices or prior warnings that there is an issue with my Partner Center account and I have contacted support for assistance without results.
This issue impacts my business to provide third-party Windows software.
Kind Regards,
Mounir Idrassiinsert your business(es) name(s)insert your business emailinsert your business phone number and any alternate phone numbersinsert your business address
Time zone : JST (UTC+9)