Someone from my school applied to catz for economics, with reasonable GCSE results (not as good as yours) and AABB at AS-level (maths, physics, economics, german). He was financial director for his young enterprise company.
he got pooled.
So I'd say you have a chance, as long as you are enthusiastic and interview well. Go for it! (I'm a little biased though as I got an offer from catz this year)