What did you originally send for those years. So those years are not covered by any type of schooling? or employment?

You will have to send more than a letter from at&t. You need to call them and get copies of your bills or payment receipts.

No doctors appointments
You did not go to any family gatherings where someone could have taken a picture of you?
No sports activities?
No other online accounts with your name?
You can also send 2 affidavits