Yo ... since no one here can see the letter read it again. If you still have questions either call the number on the notice or open your account online and look at the transcripts :
https://www.irs.gov/payments/view-your-tax-account or post back with more information starting with what is the notice number ( is it a CP or LTR and the # after it) or call TT support :
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
