Rain WIFI is trash

I really think it is ridiculous how this Wifi works. I had been trying to cancel with Rain since last year October and requested a phone call for my cancellation, yet Rain kept deducting from my account till December. The only time i received a call was from their agent telling me that I had missed my payment, which I missed on purpose because I have been trying to cancel. I was told that the cancellation would be finalized once I return their router, WHICH I DID IN MID JANUARY of 2025. WHY AM I ALSO BEING CHARGED FOR THE MONTH OF JANUARY WHEN I HAD NO RAIN SERVICES SINCE THE 25th OF DECEMBER. Last time I checked rain is a month to month service, why am I being charged for a month where I had no Wifi at all?