They don't need your help OP because they can withdraw their money successfully from the exchange site after trading the cryptocurrencies to fiat like USD. Let's say they can't automatically withdraw the fiat from a certain exchange site but I know there are third party services that allowing them to cash-out.
Also, they don't believe you because you are not providing any of the proofs as what they are asking from you.
Thanks!What services are you talking about? I talking about big money over 1 million dollar. Not one bank does not transfer such money to the exchange or withdraw it from the exchange. This money could be received as a result of ICO or mining or trading. And how do you explain the origin of money? (When you want to buy a house or bugatti))