Wrongful billing

Good day

I was offered an insurance to cover my phone I took with Vodacom contract and that was on the call . Now my problem started when I took in the phone for just a screen repair , I was told my phone is an old model and they could not repair. Then I ended up canceling the insurance because it couldn’t serve the purpose and the cancellation was confirmed over the phone But after cancellation they are still deducting my account and I will like them refund me because I do not know what am I paying for.