Many times what is stated as a free trial is not really free. You need to read every thing. I do not like saying fine print because it is not really fine. However, if you go pass the “Free Trail” and continue to read you just may see that you have to either coment to buying the product at least once or you have to cancel within a set time frame. If you do not cancel they will contine to send the product and charge you for it.
Try call your credit card company and see if they can remove the charge. Explain to them that you though you were getting a free trail and was charged. They may be able to help you.