Yes DSAR and LOC is required.
Might be a slow process but you will likely get your money back.
DSAR 1st - Analyse the info recieved back - Then LOC. Once the DSAR hits your doormat / inbox - Issue LOC to them.
BE prepared to backup with evidence the origin of the funds.
I can see why it spooked Revolut... Thats a significant amount of money.
Although potentially easily resolved if going down Legal - As long as the source of the funds is above board.
IE Savings over 2 years from valid employment. Plus if you can get Revo to cough up the info - You might find out what happened.
Keep in mind that your claim will have costs of 4.5% of the claim - Your claim would be roughly £675.
You could include damages in the amount of the claim but the amount you would need to pay would go up
It's around £15,000 as it stands.
Will I need to send the a letter before action and a subject access request, before filing the claim?
Do you know how long they have? I'm guessing due to the current climate things take longer?