I'm rather astounded at this thread. I agree that there is perhaps some merit in the 'university or not' debate, but I certainly don't think there is any here. Point and case is the new Etihad cadet scheme, where a degree is a minimum entry requirement.
Your qualifications are all about separating yourself from the other hoards vying for that rare opportunity. To do well in the ATPL theoretical examinations takes a lot of dedication, and if you are unable to achieve even an average grade at A-Level you must seriously question your ability to proceed with your professional training.
In my opinion, this is a no brainer. If you want to fly, then get your head down and start studying; I'm certain you are perfectly capable if you apply yourself fully.