Trying to purchase train tickets online at Trenitalia for our trip end of May. They are offering a great discount when purchasing in advance. My credit card continued to get denied and after $20 in phone calls to them in Italy (!), I've discovered they only accept "international" ?? credit cards. They suggested I purchase thru a couple travel agences they are affiliated with in US. I called one of them and the price is double. Does anyone have experience with this and any suggestions out there?