Travel Insurance auto-included by American Express

I have had an american express credit card since 2000. I use it every now and then but always pay it off in full after the monthly statement. Couple months back I purchased two airline tickets using my american airlines card. I used orbitz.com and it had nothing to do with the card but they charged me $30 travel insurance for each of those tickets. I realized that and called them but customer service told me the charge can only be removed by the insurance department and their offices were closed. I called back later and this time talked to an agent. She said she cannot refund. I asked why they cannot refund since I am yet to take the trip. She refused to cancel it but didn't give a good explanation. I then spoke to a customer service supervisor who said I can dispute the charge. I canceled the credit card and paid the card in full except for the amount in dispute. I was told they will find out how and when I signed up for auto-include of travel insurance when purchasing airline tickets. However, I got a letter few days back saying that I had accepted that over the phone and so they do not have any record of me signing up for this. Now I am stuck paying this $57. I would really appreciate if you could help me.