STAY AWAY unless you're sticking with this for life!

I signed up for a 1 month free trial. During registration you are forced to provide credit card details for your subscription when the trial ends, but are assured you can cancel your subscription if necessary. I would now like to cancel my subscription as I don't want to continue. I followed the instructions to cancel my subscription online, but received a message saying that I had to call them to cancel. I have phoned the number given numerous times but repeatedly get a "The dialed number is not use" message. So now I'm stuck in this subscription that I cannot get out of :-/