Sitting an A-level independently...

Slightly different option: will they not take language qualifications studied at university? As in, the evening classes that I imagine must be available within your languages department. They are often graded to a common European standard; I think the end of C2 corresponds with an A-level standard.

You'd likely have to pay, unless you have any other free modules in your degree in which to do some, although depending on the length of your degree i'm not sure if you'll have all the time available to do it completely. Worth checking though, as it does mean you can be in a classroom, with a teacher in a small class with other students to speak to. If you've just started this year I think you'll have enough time.

Edit: might actually be B2, in which case it's about ~4 semesters, so you ought to be fine.

I did a beginner's module of German during my first year, and some guy in my class was on a Spanish with French and Russian degree so kind of all walks do it.

I wish! The university does do a language programme alongside this, but you're right, I'd have to pay mounds for it since my Italian is beginners' and already takes so much time. Also, I don't have any pre-existing qualifications in French (though through self teaching I'm around GCSE standard) so they'd make me take a beginners' class in my first year, which means I wouldn't be able to progress onto "Post-intermediate" which is their A-level standard. I'd like to find a way I can leave it to my own devices and just sit the exams. That way I can keep the costs down and I have total freedom over what to work on.