Not Sure what place of study I can go to for my A-levels

Hello, I live in Barnet, London. I had plans to do an accountancy btec at barnet & southgate college. I went and enrolled so insanely late and was turned down and told to prove myself by doing a business btec level 3 for a year. I am half way through the course and regretting it a lot. My main focus right now is that I would like to do A levels. I am looking to study accountancy at university, so I'm looking to take subjects like Maths, Economics & business. However my exam results where not to great due to my lack of effort. I have ordered a replacement for my lost exam result sheet but I am sure I got a B in maths a C in business, a C in R.E Two C's in science BTEC equivalent and a C in Drama I am in a pickle and wondering what I can do, my other results I believe to be low and that I have got a D! In English.