Maybe the money they had on Revolut was malicious, so that's why your account was blocked. In this case, they are the scammers. Anyways, only Revolut can tell you why they blocked your account.
Explain that you need to know if it was due to the latter so you can raise a criminal complaint against the localbitcoins users responsible in the hope that they can be traced by law enforcement and possibly (albeit highly unlikely) recover your bitcoin/funds. In any event you are entitled to more of a response than simply, "we can't tell you", seeing as they literally emptied your account without notifying you.
At the very least they are required to advise you of the procedure you need to follow in order to fully establish the nature of the decisions they took in returning the deposits to the originating accounts. Be that through a formal complaint with them, the financial ombudsman or, indeed,
Action Fraud UKI have submitted a formal complaint to Financial Ombudsman Services, no answer yet.
I'm not the only victim, there are more groups on the Internet.