That's the thing. How do I know the recovery is genuine service or scam?
I'll just add to look specifically for those with blockchain analysis (
https://en.wikipedia.org/wiki/Blockchain_analysis) experience, I don't see how it's gonna work if they're not well versed about it. Also pay attention on how deeply rooted are they with exchanges, kyc firms etc.. cause i think it gives you a hint on how much information they can easily access.
And how can they recovery even if they can trace the account?
I'm not exactly sure but most likely gonna be settled legally.
Can they forzen the account?
Only if funds lands in a centralized platform e.g. binance, coinbase etc... Users don't actually control their funds in there so the recovery service can ask to freeze a certain someone's account if they have a valid suspicion.