Head of year didn't apply for special consideration for AS levels

My nan passed away a month before my AS exams. I was a mess as we were very close - something my head of year knew as he had cut me some slack re homework and in-class tests. I went to go see him about 10 days before I go on study leave to discuss special consideration and he said he'd talk to our exams officer - I then heard nothing more and assumed he'd sorted it.
I then see something on TSR (between exams ending and results day) about a student having to submit proof of a family death (i.e. a death cert) in order to get this in their exams. Firstly, does this mean the school didn't apply for special consideration?
When results day comes around my grades are good but I was honestly hoping for slightly higher. I'm applying to Cambridge so need top notch grades and UMS but i end up with a B in English Lit (2 marks off an A that didn't change with a remark) and lower UMS in politics than I was expecting - and lower than the average Cam UMS.
I also see nothing about special consideration being given on the exam slip.
I'm now very annoyed because that 4% I would've got from special consideration would've avoided this. Any advice about what to do now? because it cannot be applied retrospectively.