Hi Sarcasticjoe, I understand your dilemma, however it may help you to know that many universities are now accepting a wider range of qualifications.
I left college 11 years ago with only 2 GCSE's and a GNVQ Intermediate. In my opinion, back then, colleges and universities didn't want to know if you didn't have specific qualifications.
I am now a mature student and there are many options open to me. I have been studying for the City & Guilds Adult Literacy and Numeracy Level 2 which is equivalent to GCSE English and Maths grade A-C. In September I start the Access to Higher Education which is equivalent to 4 A/S Levels. My preferred University has confirmed that these qualifications will be acceptable.
I am assuming that you are a young student, in-which case, I realise that the above is not applicable to you directly, but you could contact a few universities to see if they would accept a BTEC as I feel you would be pleasantly surprised.
All the best with your final exam