Ok ... you have a couple of issues ... first you must amend the return starting with the return as changed by the IRS (column A) which would have shown the same balance due that you agreed to pay and did pay (penalties and interest cannot be counted). Until you get to that point you cannot start the amendment process ... if you did start you need to start again.
Then if the amount on line 16 is not correct switch to the FORMS mode to make the correction ...
Look at the form 1040X …
Column A should have the figures from the original return, Column C the corrected figures and Column B the differences between the other 2 which needs an explanation on page 2 of the form 1040X.
If you completed it correctly you will see an entry on either line 16 OR 18:
On line 16 should be the amount you paid with your original return. If you paid nothing already then this line should be zero.
On line 18 should be the amount of your original refund you received. If you have not received your refund yet then you need to wait for it. If the refund changes from what you expected then this line must reflect that change.
Then you will see your extra refund on line 22 OR the new balance due you need to pay on line 20.
