Well you say you've decided on LSE... but you get five picks on the UCAS form, so you may as well put down LSE, Cambridge, Warwick, etc (maybe a backup, too).
Edit :: You do realise applying for top unis for a proper course is very competitive, right?
How about taking some A levels?
I would argue the Surrey business school is not as good as it once was. The number of modules available have declined and the support offered to students is a shadow of what it once was. Not to say it's awlful but certainly not the best. It's merit is the placement year it manages well which helps it have such a successful graduate employment rate.
EDIT: My brother was in a situation where after a long term illness he was 20 with 5 GCSEs and not eligable for Uni. He's now doing an access course during the week (Law, English, History - GCSE to A level standard) which will allow him to get into uni the following year. This has worked out better than if he chose to take A-levels. It's also only £900 where he's taking it (or apparently free if you don't have an education past GCSEs). They also run them at weekends for people who have week commitments like working. Many universities accept access courses I am told, he's visited several who accept them.