Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
if its the same apple id / email address you have been using for some time.. More likely, it doesnt recognize your password.
So, use the email you think should be your apple id, and go to this link and try and reset the password.
Once the password ***** ***** try that apple id in the app store again, it should recognize it and the new password ***** just set now.
If you get stuck or run into any issues, let me know.
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.
Besides your ipad, do you have a windows or mac computer we could use to try and reset the password?
Hello again, I see you viewed my last reply but never responded. Did you still need help with this issue?
Please respond when you can so we can mark this issue as resolved or continue working on the problem.