I've recently been trying to get back into my Rockstar account that is associated with my Steam account. I don't know why the password that I would have used with it is not working, but I can't seem to log into it. I contacted Rockstar and each time they request more information, and it usually takes them about 24 hours in between requests.
This is a list of what they've asked for so far and I've given. My social club account name, my Steam account name, my Steam ID64, my GTA V CD Key, a screenshot of the email of receipt of purchase (from 3 years ago), screenshot of the Steam window showing my Steam username and GTA V in my library, and a screenshot of the Steam window showing my username and the CD Key window showing the CD Key.
I've had banks that wanted less info from me.