How long OBLIGATED to pay for service month to month?

My sister purchased a Roamio in February 2015. She stopped using it a few months after (reason not important).

On her account on TiVo.com after one year it switched from "Service Only, 1 Year Monthly" to "The TiVo Service, Month to Month." All monthly charges regardless of the category are $14.99.

It seems to me like she should have been able to cancel in March of 2016. Is there any reason why she shouldn't cancel service now? She could reactivate if she ever wanted to use it again,...

How long OBLIGATED to pay for service month to month?

How long OBLIGATED to pay for service month to month?