Before three weeks ago,
I updated and pushed few codes from my Java code editor(IntelliJ IDEA), by authorizing and connecting through GitHub.

After a few moments, I received an email that GitHub found some suspicious activity, and so I enabled two-factor authentication. But soon after a minute, my code editor told me to reauthorize and connect github account again.
At that time, github said that my account is marked as spam, and it prevents from authorizing any 3rd party application.

I have already tried creating support tickets for de-spam, and created Reinstatement Request. So far, I had created 4-5 support tickets, but GitHub support has not replied yet. I don't know any reason or policy which I have violated. I request Github to help me on this issue.