A month-by-month security contract was severed in writing on the last day of the month of May. The security business continued to charge the monthly fee on June 16 of the following month. When contacted, the security firm said the billing department received the cancelation notification June 1 and by that time, the new billing cycle had started. A refund retroactive to June 16 would be issued in July. I queried why the refund would not be retroactive to June 1 to which the response was "well that's the process". Is the compamy allowed to charge for this additional two weeks of service after the service was canceled?
If the month to month cycle starts on the 16th of the month, that may be accepted practice. When was the contract established.
A month-to-month contract is not intended to be a day-to-day prorata contract.
Also, normally such contracts have terms of cancellation. Where there any?
So depending upon data which is lacking in the question, the provider may be justified in their actions.