It may be difficult for you to prove that you actually sent the funds if they claim you never sent them.
Maybe try a small amount that you can afford to lose.
This is the lemmy community of Monero (XMR), a secure, private, untraceable currency that is open-source and freely available to all.
Wallets
Android (Cake Wallet) / (Monero.com)
iOS (Cake Wallet) / (Monero.com)
Instance tags for discoverability:
Monero, XMR, crypto, cryptocurrency
It may be difficult for you to prove that you actually sent the funds if they claim you never sent them.
Maybe try a small amount that you can afford to lose.
Problem is not that, but they got the Monero via scamming someone in Europe/US and trying cash them out now, most likely than no security researchers tracking their names/accounts
The entire philosophical point of monero is its fungible. So you don't know where that monero came from. They could be an online graphics designer getting paid in crypto. There are many options. If you're a vendor on local monero and you have KYC policies based on the origin of the money you could always ask for proof of origin for the funds. But that's going to be more administration on your end