This is why I pay almost exclusively with Amex. They do contact a vendor and sometimes the vendor tries to fight it, but if I reopen the dispute, I always get my money back (and I dispute a lot of transactions).

I have the opposite experience with Mastercard. Of the dozen or so disputes across 5 cards I had over the years I essentially lost them all. Visa is somewhere in the middle. They tend to side with customer but also will investigate thoroughly.