According to what you posted in another thread, you sold the domain name, and the purchaser used a hacked paypal account to pay for it.
I'm going to guess, then, that you consider this domain name "stolen" in the sense that you were defrauded of the payment, but not "stolen" in the sense that your account was hacked and that the domain name was subject to an unauthorized transfer.
The registrar is not responsible for you having voluntarily transferred the domain name upon your acceptance of an invalid payment. Registrars do not get involved in sorting out people's contract issues for them. If you moved the domain name out of your account, or whatever, the registrar has no way of knowing why you did it, and certainly no way of verifying what the terms of your sale contract were, if you got paid, or if payment was reversed.
I'll repeat what's been said in this and other forums a zillion times - taking paypal for a domain transaction that is important to you is sheer madness.
But what is it, exactly, that you want the registrar to do, and why do you expect the registrar to do it?