Refund Delay

I have used Turbo Tax for 8 years now.  My Federal form was accepted on 2/12.  To date, I have not received a refund.  I filed electronically and gave direct deposit info.  I received my State refund about 10 days later.  I have had 2 conversations directly with the IRS (one at 9 weeks and another at 11 weeks).  I have received no direct answers.  I have also not received any IRS correspondence via mail.  My return is a very simple one:  retired, filing jointly, standard deduction, some solar panel credits.  I have now been asked to call back mid-May.  How can I get closer to an answer?