My mother (against my strong advice) booked something on booking.com for ~$6.5K and then couldn't find any evidence of in their "My Trips" interface. I advised her to call the credit card and file fraud. Instead, the customer support agent of the credit card gave her some 1-800 number for booking.com customer support (Booking.com doesn't offer 1-800 number) and when she called it, someone with strong Indian accent wound up resetting her google account and tried to take over her Gmail. Fortunately I made sure she was 2FAd there, so between her calling me panicking because her mail was blocked and us recovering it only took ~20 minutes. The credit card company refunded her money, and the hotel she was trying to use gave her a great deal and she's out there right now skiing. So all is well. But never more booking.com for her I am pretty sure.