12c letter

I received a 12c letter asking that I fax all of my withholding information to the IRS. It said it would take 6-8 weeks to process my refund, It will be 8 weeks this Friday since I faxed the information requested and have heard nothing back. What would be my next step? I check where's my refund every day and have called the IRS about 4 weeks ago. I've never had a problem using Turbo Tax before.