Yes you need at least a C in maths to study anything at A levels.
Thing is, I haven't achieved a C. Though I'm curious as to if it's possible to retake maths alongside my a levels. Keep in mind that this retake - when passed - will be my fifth GCSE.
In the college I'm going to, the teachers said that I need to call them immediately if I don't achieve a certain grade. So I think you could try talking or emailing the exam officer in your school about retaking an exam, or phone someone in college who deals with retakes.
I don't think you'll be able to until you pass maths because most sixth forms across the country require a minimum of 5 A*-C before you can continue to a level. Try to speak to your college about it as they may be able to sort something out for you
Most require 5A*-C as everyone else said, so you need to ring the sixth form and ask them directly as you didn't achieve this and then it's up to them anyway. Don't you have to retake maths as the government require at least a C in English and maths?