7 marks is not childsplay and whatever you may feel about the examiner you need specific areas where you were undermarked and solid reasons why if you are going to get upmarked
even if that is the case, you are quite unlikely to get the full 7 marks worth and if you don't gain any marks its money for nothing - especially if you got into your firm choice (or a university you're happy with)?
you may just have done slightly below your expected when it came to this one time
speak to your teacher aka get a professional opinion