AppleID is locked no access to phone number

Hi, my appleID is locked (wrong password). It's impossible to get a veryfication by phone because I gave a wrong phone number. I contacted with Apple Support but they wrote me that I need to have a invoice. And here is a real problem - IPad was a award so I have any invoice. A firm which gave me the iPad send a letter with an explanation that I won it in the competition but they also have any invoice because a firm which gave to them the iPad don't exist nowadays. So: 1. wrong password 2. no access to phone 3. no invoice. What can I do in this situation?