Charged more than refund to cancel car insurance

So I recently bought a new car, and scrapped my old one. I had insurance with 1st central on it, paid for in full at the beginning of the year. I phoned them to cancel and they charged me £13.10, the breakdown of the cost was a £36.90 pro rata refund, 3 months left on policy, and a £50 cancellation fee.

I understand it's policy and would be fine not getting any refund but it seems unfair to change more just to cancel. Has anyone had any luck complaing or know if I can get my money back? Thanks