First you will want to verify that you are actually due a refund relating to the tax law change. You can do this by generating an amended return in TurboTax. You will not need to actually file it. If you need assistance, feel free to click on the Live Help icon within TurboTax to speak with a Tax Expert.
Once you have verified that you are actually due a refund, you will want to check your transcript on IRS.gov to see if IRS has recalculated your tax return since you originally filed. If you do not see the recalculation, you will want to contact IRS directly by phone.
https://www.irs.gov/individuals/get-transcript
The phone number to reach IRS is 1-800-829-1040. We recommend calling at 7am.