Unless you are also a multibillion dollar company, There is close to nothing you can do to sue roblox. Lawsuits are not DIY projects. You will need to go to a lawyer, tell them your problem, and get them to do the lawsuit for you.
Full Answer
Unblocking Doesn't Work!
As noted, you're free to arbitrate your dispute, which is like a private lawsuit. Make sure to review the terms you agreed to so you know the dispute resolution rules, and as also noted, be prepared to pay a lawyer substantial fees unless you plan on representing yourself.
Nope. "by accepting these Terms, you and we are agreeing to arbitrate any dispute between us, and you are giving up your right to go to court . . . "
Roblox is a great community of players and developers of many ages, and we like to encourage a safe and fun environment for everyone. If you see other users breaking the rules, we have tools in place to help you report any inappropriate behavior.
Use the Report Abuse feature in an experience to report the specific chat or other content that violates Roblox rules. It sends the information directly to our moderators and allows them to see what the other user is doing wrong.
If you find users or content breaking the Roblox rules, use the Report Abuse feature located throughout the apps to report this to our moderators. There are different ways to report based on what is being reported, but anything you see can be reported.