Good service but has a Cancellation fee even though it is not a contract!

They provide reliable internet and the transfer to their service was quick and easy. However in terms of the cancellation it is very *****. They say that the the deal is month to month but then when I go to cancel they say there is a fee because I have been using the service for less than 12 months. This makes no sense because I was under the impression that it is month to month.