I've used MyFax for a couple of years and found I didn't use the server very much. Last year I contacted them to cancel and they said you need to do it verbally before the "auto-renewal". So I said fine but do not auto-renew in 2013. They did anyway! I contacted support and they claimed to have put through a reversal even thought it wasn't their policy. Didn't receive any credit so far.
These auto-renewals are a scam, they process you CC the same day, but can't reverse it when you want to cancel the service. DO NOT do business with these people.