There isn't much you can do. Try following these steps
Recovering hacked/lost accounts. There is also the
Cryptios team which handles account recoveries you can check in at that topic and see what else can be done if anything. They can see IP info and some other things that generally can help them determine account ownership.
Note to everyone else
Stake an Address somewhere.
I have no BTC address and cannot give signature... This is my big problem...
"Signatures
Often, you need to prove ownership of the account with a PGP or Bitcoin signature. This has two steps:
1. You need to show that the PGP key or Bitcoin address is associated with the account, for example by referencing an unedited post in which you posted the address.
2. You need to sign an appropriate message with that key/address.
For example, this is an example of an appropriate proof of ownership:"
As I understand, my last hope - Cryptois