Earlier quoted context omitted.
Speaking as someone who used to hire low-level developers in the financial sector (i.e we could pay them an above average salary) I'd disagree. There's only a handful of universities now which teach C to a decent level, and if a candidate doesn't know C already it's very hard to tell if they'll be able to conceptually handle pointers and indirect referencing. So there's actually a very small pool to recruit from comp…
A lot of finance companies have rejected me for placements for low A level grades despite high firsts in all my CS modules, solid extra curricular's etc...
Hence companies relying on A-Level scores and university reputation when filtering.
What ECs do you have ? - that's probably your best bet of getting visibility. Assuming you're a second year student you might want to apply for a GSoC on a low-level project.