Should I redo another year at college or go to the uni I got into

I got my results in August and did somewhat poor, B in Business, C in Economics, C in Graphics Design (despite getting B's in AS & A2). So, I was unable to get into my firm choice uni (University of Manchester Business School) but got accepted into my insurance choice instead (Aston Uni Business School) however, I did some more research on Aston and realised that it wasn't really for me. I tried applying via clearing to a Cardiff Uni because it's close to me but I was rejected.

So, I've been considering in doing another year of a-levels with the same subjects to improve my grades for a better uni. I just enrolled for another year at college today but a part of me regretted it instantly and wants to move on with life and go to uni, but I don't want to settle for an average uni (no offence). My priority would be to go to uni but a top tier one. Could anyone give advice on what to do?