Originally Posted by
view-with-a-room
With PNR / ticket number and last name the noted information is available via the alliance public airline booking management systems. Flights booked with BA for AA flights can be managed with the RJ booking management system, as an example. Providing personal information to an unsolicited contact is not good practice.
And airline ticket issuers can routinely refund tickets for cancelled flights without being given the bank card details again.