BAD Service

I subscribed to rain because it is a month-to-month service and I already have a contract with another service provider for work internet. When the premium didn't go through because I changed my account details, they stopped the internet service immediately and collected the router. Today to my shock, I called them to activate a new service for the upcoming holiday season and I'm told that I owe them for 2 months of premiums even though their service was disconnected on the payment date. The person then proceeded to say I was given a grace period for 2 months while I was still using the device which is not possible because immediately after they deactivated, I packed up the router back in the box ready for them to collect it. I find that this is not acceptable to me as I took the account on the pay as you use basis and now I'm being thrown a curve ball to try and get more money from me for a service I didn't receive. REF***1