Deductions after cancellation

I cancelled my 5G Rain service in September and returned the router at that time. I had already paid for October, even though I did not use the service after cancellation. However, at the end of October, Rain still deducted money for November, which should not have happened since the service was cancelled.

Please explain how deductions are still being made for a cancelled service. I also request an immediate refund of the November payment and confirmation that no further deductions will be made from my account.