So yes. The original return had a 2,000 refund. But with the extra interest it should be you owe 1,500? Then yes you owe the 2,000 back plus the real 1,500 tax due. They should still send you the 2,000 refund unless the catch it and just it for you. That's why you should wait to amend to see if you get the first 2,000 refund.
