unjustified enrichment from their cancellation process or lack of process

I called to cancel my dstv services before the next premium was raised, I was told they would escalate to the have it cancelled. it has been a week and the next premium has raised and I have been told I am liable for the premium. You have disconnected my service and expect me to pay a full premium for a service that I will not be using. This is unjustified enrichment and it is ***** you guys are cheating us and punishing us for cancelling your services.