So you mailed them your 2017 return after they said they didn't get your efiled return? And they sent your mailed return back? Now they want you to send it by mail again with any attached W-2's, 1099's, etc. that show withholding?
TurboTax does not have copies of any of your W-2 forms, 1099's, etc. It only has the info that you entered from your documents. For W-2's it places the info on a worksheet called "W-2: Wage and Tax Statement." For 1099's, it uses 1099 worksheets. Those should be in your 2017 PDF if you saved the PDF with all the worksheets. If not, you can try downloading a new instance of the PDF to see if the rest of the worksheets are there now. But that is not an official W-2 or 1099, since it is self-entered by the user and not an official document from your employer. It will tell you what you entered, but likely won't satisfy the IRS since it's self-entered and thus could be manipulated by a user. That's why they want to see official documents.
See this FAQ: How can I get a copy of my W-2?
https://ttlc.intuit.com/community/forms/help/how-can-i-get-a-copy-of-my-w-2/00/26328
