Signed up for wronng course number that was an honors cl and now have a bad grade?

ok so last fall i signed up for this cl, at my community college, they combine the honors and regular cl and the honors cl does more work. So i thought i was in the regular cl but i somehow mistakenly signed up for the honors cl and did not do the work for it so now i have a failed grade since the course numbers were almost the same, i know i should of doubled check. Has this ever happened to anyone and if show what did they do and how did it turn out? I am in the process of talking to the professor to see what can be done.