They can't change your Security question unless you did not use the one time option to do so in August. They also can't change the name on the account. The worst they can do is change your email and password. The only department that handles compromises are the GMs so you will have to re-submit a ticket.
Also, if you have not figured out how the compromise happened, then they will get right back in, which may be why you see odd things gear wise. Most likely you have a keylogger on the PC. Please follow the security recommendations in the compromise link below. Malwarebytes is a highly recommended program and is free. Scan with the FULL scan (not quick) and do it with the game up and gibberish in the login fields. When done, repeat with a FULL virus scan with an up to date virus scanner. Feel free to try a few things as they have different definitions.
This article leads you through the compromise process. https://us.battle.net/support/en/article/compromised-diablo-iii-account
Once you are VERY sure the PC is secure, request your roll back and they will put it back to whatever save point they have (warning it may not be a save point you like)
Also, if you have not done it already, get an Authenticator! That won't keep keyloggers off your PC or hackers out of fan sites you may have logged in to, but it will keep them from getting into your Battle.net account.
P.S. Your email is likely compromised as well so you want to change that password too once the PC is clean.