International Nurses Association Scamming Money Out of Me Twice! New York New York

I received a letter from the International Nurses Association previously which never mentioned anything about money (which I still have) and it clearly states that there is no fee for membership. I received a call from a person in New York on November 6th, they sweet talk and don't mention anything about money until the end, I spent 45 minutes with this lady! (But she seemed nice.. or that was part of the scam, not sure.) Either way I gave out my credit card even though I was hesitant and she wouldn't even email me any information (which I found strange by the way). And now the charge ($218.95) is currently charged to my credit card with me trying to dispute it and it being put back on as this organization has provided some info to my credit card company. Tried calling the person i spoke to and left a voice mail to return my call. No call received yet. Tried to cancel my "membership" from another representative and she just states that all memberships are final. It hadn't even been 24 hours at the time. Now yesterday (January 13th, 2014) I get a call and get scammed out of another $189 fom a John Green (who i called by the way and have not received a call from). I called my credit card company and they connected me to membership services who are not willing to refund me the entire amount. The guy never mentioned to me directly that there is going to be a charge on my credit card for this "book" that will come out this year.