I need Help!!

Am a student presently doing A-levels at a 6th grade college in Nigeria. Presently, am getting fed-up with the system and am presently looking out for a way to do foundations instead of a second year in A-levels.

Well, I have chosen to do foundations in the UK but I am presently facing three major challenges; good schools that offer foundation courses that at the end am guarateed admissions at UCL, LSE, SOAS, Queens Mary and the likes; affordable fees and then the fact that admissions for this schools are highly difficult.

This however, has led to depression because I can hardly get what I want....
Is there anyone who can help me with reasonable information as to how to work this out in the simplest way possible.
Thanks.