Stolen camper rental deposit

[PinkTurnip85]

Hello, any advice would be much appreciated... We rented a campervan through Yescapa (like Airbnb for campervans) and the owner has not returned our deposit. He said he paid it to the wrong account details and then stopped returning our messages. Yescapa threatened to ban him from their platform and cancel all his bookings if he didn't return our deposit, but he ignored them too. He has now been banned from Yescapa, but we are still 500 euro out of pocket.
Yescapa have said there is no more we can do and just advised us to 'take him to court'. He is in Portugal, so I don't know where to start with this.
Can anyone advise what legal action would entail and how much it would be likely to cost? I'm assuming it's not worth it for this amount of money (legal costs would be more than 500 euros)?
Would legal action likely mean anything or could he just ignore any judgement?
I have loads of messages from him admitting it is our money and emails from yescapa to confirm we are owed out deposit back.
Thanks in advance for any help.

[Manxman]

Did you happen to pay either by credit card or by debit card? If by credit card you should be able to make a claim under s 75 of Consumer Credit Act 1974 (legislation.gov.uk) even though the transaction was overseas. (I assume it was overseas if you paid 500 euros as the deposit). Contact your credit card provider.

If by debit card you might be able to make a chargeback claim. Contact your bank.