Confused on how to Amend

I received a letter from IRS that they are holding my refund because there may be errors on my return.  I am trying to amend on TurboTax because there were some errors.  The fixed info decreases my refund.  Turbo tax is assuming I already received my refund so the amended return says I owe money.  How can you do an amended return on turbo tax that shows you never received refund?