Whilst I feel for you- it will be hard for you to get accepted- which is a real shame. However, think about it from the uni's POV and from that of other Commerce students. Personally, I had to choose methods (a subject that I really hate) over Legal- a subject that I like- just to meet to pre-requisite for Commerce. My ENTER was affected- because I would have definately got a higher score had I not chosen Methods. However, I spent a lot of time this year- fighting to ensure that I stayed on top of methods. It hardly seems fair that you get a higher ENTER score than another person- and then try and waltz in to get a spot in commerce, especially given that you had the opportunity to take Methods again.
Whilst it does seem harsh- the uni will argue that the type of Maths required to complete the commerce course- would require at least a 25 in a raw study score- and by allowing you in- it would set a precedent of other students who would "just miss out" on the pre-requisites
I hope that the Uni bends the rules for you- as you seem more than able to complete the course- however, I highly doubt it will happen.