Q: my apple id had been lost and can't activate it now

Here's what you can do:

If you can't remember your Apple ID, follow these steps to look for it:

1. Go to My Apple ID (appleid.apple.com) and click “Find your Apple ID”.
2. Enter your first name, last name, current email address, and any prior email addresses that you might have used to create an Apple ID. Apple uses this information to search for Apple IDs.
   • If no Apple IDs are found, follow the onscreen instructions to create an Apple ID.
   • If one Apple ID is found, choose whether to receive an email from Apple or answer security questions. Both options will conclude by asking you to reset your Apple ID password. Follow the instructions provided.
   • If multiple Apple IDs are found, select the one that matches your current email address. Then choose whether to receive an email from Apple or answer security questions. Both options will conclude by asking you to reset your Apple ID password. Follow the instructions provided.

Additional Information

• Changing your Apple ID
• Where you can use your Apple ID
• Changing your Apple ID password
• What to do if you forget your Apple ID password

copied from Apple ID: How to find your Apple ID

Maybe you should contact Apple Support directly and see if they can do something about that.

Apple - Support - iPhone - Contact Support