Bad service

I’ve paid Cartrack a cancellation fee of R721,16 because I had a car accident in February and my insurance company declared my car written off. Cartrack deducted my premium for February fine it was already due and uploaded so I questioned why they deducted in March because there was no car that was being tracked they went on about my nature of contract I let it go then paid them the cancellation fee as they said I’m cancelling my contract also asked them for a cancellation letter to prove that I cancelled and they emailed it to me only for me to see today that they’ve deducted money from my account again this month I am not happy and I’m not having it I want my money back.