How were you supposed to have received the 2017 refund? By direct deposit to a bank checking account, or direct deposit to a prepaid debit card, or by check in the mail? If a prepaid card, was it the Turbo Prepaid Visa Card?
Did you have any TurboTax fees, and if so, how did you pay them? Did you choose to pay them upfront when filing, or did you choose to have the fees paid out of the Federal refund?
When you log into your Online TurboTax account, go to the section "Your Tax Returns & Documents." Expand that section and choose tax year 2017. What is shown for the 2017 return "status?" (also the status of any state return, if applicable.)
We can tell you how to reach a live agent at the IRS once it's clear what the details of your situation are.