1) The user has intentionally broke the rules of the service, committed a fraudulent action and put the guilt on the nominee. We are fully sure that truth is on our side.
2) The user lies. "this was a coincidence and came from one of the exchanges we have used" - it is obvious and well known that crypto=>fiat exchange does not function as a mixer and has one fiat "output". The entry point was the crypto which you have sent to the exchange. The exit point was the fiat funds sent to the debit card which has been used by you at that particular point of time. You are trying to veil your fault.
3) We have blocked the card in order to secure another nominee, whose account/debit card you had in use. There was no intention to block any funds. The funds is still in the account, not a single cent has been touched until there is a clear path how this situation will be resolved.
4) It is obvious that blocking 1700 EUR to risk the reputation we have built through years is irrational, it has been done for a reason. We have clients for whom we have managed complex tasks of unlocking binance accounts with balances worth of 100k+ USD. Risking the reputation for 1700 EUR is absurd.