Account accidentally deleted - "email has already been taken"

One of my home users has accidentally deleted his account. It has been used with google login. Now I try to re-register this account, but I always get the error “email has already been taken

I have the mail-address, google account and password, but no chance to re-register this account.

How can this be resolved?

contact https://www.plex.tv/contact/?option=plex-pass-billing