I would not be able to do anything because they instantly blocked everyone's account. But if they had not blocked accounts, I would have sold the amount because the money in my account is mine haha. At least at first glance, I would have gone crazy because the amount they sent is not small. 2490 BTC in my account haha, I would have gone crazy for sure.
How not crazy... that's millions of dollars just dropped in my account. Lol for sure I will scream for joy.
I can only wish to receive such a huge amount in my non-custodial wallet. What if they had asked for a wallet address, not from the exchange? Well, that's why they always ask for a UID. Maybe the mistake might not have happened in the first place if they had asked for a non-custodial wallet address, because at least the network could tell them something was wrong.
I have yet to see an event or airdrop held by an exchange asking for a non-custody wallet, they will definitely ask for a UID as ownership of the account, whereas asking for an off-exchange address can be disastrous if the exchange makes a fatal mistake like this... try to imagine 2000 BTC being sent accidentally to a custody wallet, then the exchange can't do anything after that.