I purchased a product at an introductory price with a recurring charge. At the time I placed the order I told them I was getting this for a friend with pain and that I did not want to start a recurring charge - "she could do that if it worked"

Right after the purchase and item received I would have cancelled or set my calendar reminder to cancel because most introductory offers will bill 10 to 30 days after purchase, it's in the fine print

I would reach out to the BBB if you have contacted the business in question and informed them of said intentions when the product was bought. Has the business in question been contacted about said charge? Have they refused to stop, or refund said charge?