The IRS should be able to calculate how much tax you owe, or the size of your rebate, without you having to fill out tax forms.
Why not let the IRS send you a form where you agree or disagree with their calculations?
If you agree, you either; i) accept to pay what you owe, or ii) receive what they calculate to be your rebate.
If you disagree with their calculation you submit your own tax return.