Unfair insurance practice

I have canceled the insurance on 2 devices with immediate effect on 28 August 2024. The agent told me that the premium will still go off at month end but the devices will not be covered till 30 September 2024. The insurance stops with immediate effect. I don't understand because I've already paid until for cover until end of August 2024. Now I have to pay until end of September for devices that's not covered under the canceled policy. They can take my money but don't extend the service how is that possible. What am I paying almost R900 for???? Worst company ever after so many years of my loyal support and diligent payments I'm done with Vodacom.