After you file

Ok ... you SHOULD have paid the original balance due BEFORE you filed the return.  LOOK at the 1040X line 16 ... does it show the amount you actually paid with the original return?   If not enter the correct amount and recompute the bottom line ... do you still have a refund or owe ?   If you owe send in that amount now and when the IRS finally processes the mailed in amended return (expect it to take 4 to 6 months ) they will balance the amount due.