Kucoin takes over any remaining Crypto funds of accidentally deleted accounts. Please explain how this is not robbing?

What happend: User deletes his Kucoin Account with 1ETH in it. He contacted Customer Support of Kucoin and they say its gone.

Facts: Kucoin didnt lose access to the Coins. So they still have the whole funds of that person, it just suddenly became full property of Kucoin.

Can someone logically explain me how this is not robbing?

We have a "client-company" - relationship here and not a "person and his personal wallet" - relationship. If it was his personal wallet and he lost access to it, well thats crypto. But in this case he is a client of a company and the company is in full control over his money and the client is handling his money on a companies website designed by the company. If the company fucked up to prevent this from happening (other exchanges have this integrated so its not out of the world) can you seriously give the client the responsibilty that he fucked up and thats it? Take in mind that the coins are not gone. There are still there, kucoin just refusing to send them to the person.

Again: We are not talking about a person fucking up his own wallet. This would be a basic and valid "well this is crypto you are responsible for your wallet" - case. BUT HERE we are already talking about a centralized organization having full control over your coins. So Kucoin controls your coins - like a bank - but when you delete the account, the arguments change and suddenly its the "you fucked it up yourself it was your crypto your responsibilty" argument?! What!? NO IT WAS NOT HIS CRYPTO AT THIS POINT. Kucoin had full control over it. This is just robbery.

Since the majority of users in the kucoin subreddit defended the action of kucoin, i wanted to get a second opinion.