Well done, if your marks had stayed exactly the same though i don't feel you would have been in a position to complain, you are applying to a place so competetive that only one in ten applications starts a course there, it would be unfair on the unsuccessful applicants who do get straight A's but didn't get an offer. Yes it's annoying but if you don't make the cut-off point you don't deserve to go there.
Seems you do deserve to though, good luck there.