Exchange with the community
What is the mood of the crypto community towards this service provider? Are there any allegations that the user is cheating? It’s not so much about general allegations, but whether other users have really experienced the same thing.
If you are dealing with large amounts of money or many in the community are concerned, it can be helpful to examine the blockchain of the respective cryptocurrency more closely. The procedure here is similar to when your own wallet or a transparently viewable smart contract has been corrupted: On-chain analysis is ideal for residents.
Searching for traces: the art of on-chain analysis
The blockchains of Bitcoin and many other cryptocurrencies, contrary to their reputation, are quite transparent. There are exceptions like Monero, MimbleWimble or ZCash that are anonymous. Most of the blockchains are pseudonymous. The identities behind the addresses are unknown, but the money transactions are visible to everyone.This can help those affected. Especially if you know the wallet addresses. With these you can try to find possible transaction channels. Block explorers like walletexplorer.com or oxt.me.