I doubt very seriously that you will get your money back from these people. What you do need to do to cancel is call them and get a cancellation # or they will never quit hitting your card. I just mailed my tea I didn't want back today and I sent it registered mail so that someone will have to sign for it and thereby acknowledge receipt of the product and the cancellation. This was what the Attorney-Generals office in my state recommended.
Here is the phone # 1-866-544-6590 (Power-Tea)
They told me that you can't cancel via the internet, you have to call them and get the aforementioned cancellation#.
I've contacted my credit card companies and told them not to allow any more charges but too little, too late. The reality is you don't have much recourse. Call them because they are counting on the fact that most won't, I suspect. Good Luck. I mean it.