When I called Juno to cancel the service

I don't have any agreement with them. When I called to cancel the service, the customer service rep said: "OK, I will cancel your service. Here is the confirmation number. I will give you one month free"
I said: "I don't need one month free, because I am going to use cable." She said:" That's just a backup service for you." I said:"Ok, then."
There's one month no charge. After this month, they restart to charge again. Because that "one month free" is for charge again after one month. And the rep never tell you the truth.