Return of deposit for rent

Good day. Please tell me, guided by which laws, it is possible to make it clear to the realtor that my funds, which were transferred to him as a pre-deposit amount for renting a house, must be returned. But as it turned out, they have documents in the form of photos and photocopies and not all of them, but the owner and co-owner are not in Ukraine. I did not sign any contract, but they say that the contract states that the money will go to the owner as a penalty due to the fact that I did not agree to enter into an apartment rental contract.