If you did not file your 2017 return, this Turbo Tax FAQ will show you how to complete your 2017 if you need to complete it.
How to complete a prior year.
https://ttlc.intuit.com/replies/4186197
If you filed and did not receive your refund, you will have to contact the IRS.
How do I contact the Internal Revenue Service (IRS)?
https://ttlc.intuit.com/replies/3301592