I don't suppose a college would want to stop you if you're motivated enough and can afford to pay for it. No idea, though, whether you could get another A24+ loan (or equivalent funding) if you've already had one to fund the first Access course you did.
If you need to do another Access course to be competitive for the type of degree course you now want to do, fair enough, but I'd suggest that doing it again simply to improve on the results you got the first time around isn't really worth it. I believe that plenty of people who don't particularly excel at L3 (A-Levels or Access) can pick their game up during a degree and get a far better class of degree than their L3 results might have forecast they would. Once you get to that stage, the degree itself is the important thing, not how many distinctions you got on an Access course.