Ip pin not working

I requested a ip pin this year and received one but when I entered it and submitted my electronic e file it keeps getting rejected. The code that is showing up keeps referring to there being a problem with my ip pin. I know its a correct code because I've checked quite a few times. Ive resubmitted several times and it keeps coming back rejected. This is my first year using a ip pin so I know its valid for this year. No one seems to be able to help me.