If you explain what the state tax dept. is alleging and what was wrong with your return, you may get comments in this public forum. Don't post any personal info. If you decide to mention more details here, then also mention what state it is and what tax year.
You can also phone TurboTax free Audit Support Center to see what they advise in regard to what caused your state letter and how to respond. At the page below, click the blue "Get Help" button and follow the prompts. It will say "IRS Letter", but they help with state letters, too.
https://support.turbotax.intuit.com/irs-notice/audit-support/
