Social Anthropology SOAS 2018 application

Hi guys, I need some advice and I have a few questions, I'd appreciate any help

I' ve already done one year of uni at another London uni but am reapplying after dropping out (I don't have any grades or anything to show for the year) and taking a gap year.

My grades are BBB and I just got rejected by SOAS for Social Anthropology. Is this because of my grades or just my application being weak? Because with a similar application but higher predicted grades, I got into UCL my first year so I don't know if it's because my grades this year are lower than the requirements (AAB-ABB).

My grades aren't too far off and I really think SOAS is the best place for me, is there any way I can reapply through clearing or is there no point because my grades aren't as required (are they lenient with grades)? Should I refrain from applying through clearing because I've already been rejected (is it possible for me to get in if i reapply through clearing)? Is there anything I can do in the meantime (until clearing opens up) to boost my application to make it suitable for them to accept me?

Sorry for making it long, any advice would help, thanks in advance!