Careers with an Economics Bsc

If I were you I’d really lock in for a - level, hopefully you could then get AAB or above in the actual exams and then take a year and work or build ur cv and then apply grades in hand for the following year

Just remember that many graduates go into careers that are not directly related to their degree subject. Employers value the 'higher thinking skills' that all graduates have and often the actual degree subject is not important.
There are thousands of career paths open to you - and there will still be other ways of working in the Banking industry if you actually still want to do that when you graduate. If you can, pick a degree with a placement, work-experience, or study abroad - this will make you a much more attractive candidate to any employer and it can often lead directly to you first job.

The problem is that the uni's that ask for the higher grades also require Maths A Level, which I am not studying.

Some don’t, given u dont take it thats the only way