If this is the stance Roobet have taken, the OP cannot really take this further except to appoint legal expert to start court proceedings because Roobet have stated their position. Having said that, I think we all probably agree the chances of Roobet scamming someone for $3000 is zero. Maybe there is more to this matter than meets the eye.
OP's account [as previously brushed on other page] was suspected to spread malware that prompt them to lock for investigation, back in 2022. Apparently, that investigation was not conclusive and someone probably accidentally opened OP's account, not knowing that an investigation was instructed to be done to the account, and effectively [since the account is opened and all would probably assume there is nothing wrong and/or the investigation is done] made the investigation inconclusive.
All of those "maybe"s and "probably"s on above paragraph said, the bottomline of my recent communication with Roobet is that OP's account is locked for criminal investigation and that OP has full knowledge about this. I personally think this is the end of the case. There is not much we can do or inquire due to the nature of the investigation. I believe they will update us once the investigation completed and they found nothing wrong with OP's account.