After you file

I filed on January 28th and state was accepeted the same day and the federal return was accepted..My TT has both bars full..WMR says its still processing still to this day anf i recieved a letrwr from the irs March 9th regarding they need to verify either my income, my income withholdings, tax credits and or business income..does that mean my refund was sent out and i just never recieved or they still reviewing..How much longer or whats the issue??