Hi, I'm Robert and I'll be helping you with your computer question.
The companies that sell in this manner are usually not dependable.
Any "free sample" that requires you to give them a credit card number is ***** free. Even when they say money back guarantee they often have scams where you have to pay for the used portion ( though how can you try it for free if you don't use it) and they have shipping and return charges that are as much as it would have been to just pay for it.
What you want to do is call the phone number on the back of the credit card that you used and tell them that you DISPUTE the charges because it was a free sample and you never authorized them to charge you.
the credit card company will return the money to your account and probably issue you a new credit card number so that they can not continue to charge you next month.