Unlock stollen iphone

Good afternoon. I am asking you for help. My name is Vladimir, I live in Ukraine, I have my iphone 5s, which was bought in the MOYO chain of stores, I have all the purchase receipts, the box and the phone itself, but alas, a few months ago it was stoleт... Yesterday police called me and they find my phone, which they took from the thieves. But unfortunately they hacked it and used another icloud account for it and now it is blocked. I ask you very much to help me unlock it and register it to my icloud to which it was activated from the date of purchase. I can provide you with all the information, photos of receipts and everything you need to unlock it. I beg you to help me with this. Thanks a lot in advance !!!!