You don't give them back the original refund.
The original refund should show on line 18 of your 1040x.....and as long as it is showing there, everything is figured-in, so the $$ you sent in with your check is effectively paying back some of that refund.
You shouldn't send in a 1040x until you actually receive the original refund.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
