You're in the equivalent of this situation:
"Activation Lock for iPhone, iPad, and iPod touch" is a security feature with an added aspect of possibly deterring re-selling of stolen devices. To learn more click here --> http://support.apple.com/HT201365
For an individual to remove an activation lock this absolutely requires the information for the account that applied the lock. Click on this link to learn 'How to remove Activation Lock' --> https://support.apple.com/HT201441
For help dealing with lost Apple ID or password:
• "If you forgot your Apple ID" [this is likely an email address you are using or used in the past] click here --> https://support.apple.com/HT201354
• "If you forgot your Apple ID password" click here --> https://support.apple.com/HT201487
Alternatively:
Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Do this online at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not state what currently constitutes proof. Prior to this new online service Apple typically required the original receipt issued by an Apple Authorized dealer and documented provenance (so typically it would be the original owner who does this, or a descendant with legal proof of ownership).
Alternatively Apple Stores used to provide this service but I do not know if they still do.
