@mecca alim - be absolutely sure it was e-filed. have you tried to access the where's my refund link or your account transcript at IRS.gov - that could provide clues on what occured.
the IRS does not want people submitted a 2nd return - that just slows everything down.
paper filing will take 6-9 months to be processed; efile, if there is nothing unusual, normally takes 3-4 weeks, that is why I suggest making absolutely sure the return was e-filed (there should be some email confirmations that it occured) ...and if efiles, there is really no way for it to get lost.
one clue - did you get the state refund back? if the state refunded and the federal didn't, at least you know the efile occured and the IRS has it. if you didn't get the state, call them (probably easier to get through and see if they have record of the efile - if no, that is a clue that it really wasn't efiled to either the state or the IRS.
