Hi zgatenadze! I'm so sorry that you're in this situation. Unfortunately, if the phone you purchased is still locked to the former owner, we're not able to assist. T-Mobile can not legally release any records regarding device history to anyone but an authorized account holder - so while we may have a phone number historically associated with an IMEI, we wouldn't be able to provide that because of privacy laws. On Apple's part, I know they've done an excellent job of creating a great Support page that outlines the steps users should take before selling their equipment - hopefully the original owner will review their devices on iCloud and realize that they've still got the phone associated with their AppleID and remove it at some point. Really, the best suggestion I can offer in the interim is to contact the person you purchased it from on EBay. Even if it wasn't theirs originally, maybe can put you in touch with the person they purchased it from. Best of luck!