iPad now in Activation Lock after restoration. Now what?

I plugged my iPad into the computer with its iTunes account to restore it because I haven't used it in years and i was locked out once it restored it gave the iPad a different serial number then the one on the box and a different apple id then what I started with. I purchased this iPad in 2012 I don't have a receipt anymore all I have is a store # and transaction # and date of purchase.

[Re-Titled by Moderator]