received bottle I did not order

I received the free trial offer.  I found it did not help my problems.  With about  3 pills left I received a bottle I DID NOT ORDER. About 3 days later I put a couple of slips on the unopened bag Send back to Sender.  I do not want.  Then I saw on my bank stAtement I had been charged for the bottle sent.  Which I have sent back like I said.  How do I get back the $76.10  that has been charged to me.  My e mail address is lmjmother@gmail.com