Few weeks ago I failed CCNA 640-801 with a marke of 696

I got somewhat disappointed as I had studied hard, I used Todd Lammle's book, used simrouter AND I know networking as I went to college to study it for one year.
Now I'm thinking to take the exam in two parts: 640-821 (INTRO)
and 640-811 (ICND). Should I do that or should I study more and take 640-801 again? I am two minded on this and I really need your advice. Of course it's different for everyone, but give me your ideas.
I really need a CCNA.