I recently signed up for their club, like any company that I am not familiar with I only used a gift card to sign up. This way there is only so much on the card to begin with. They can't bill unless I like the product and update credit card info.
This goes for any company ,I save my actual credit card for companys I trust and have history with. I never give out my checking info. Never. If they keep sending you things after you have verbally or in writing the products are yours. I would put t he cancellation in writing and send it certified mail.