Ok guys, the pet thing worked for me. Here is what happened.
- Ticket booked and charged to another card and cancelled refunded there 8 hours later.
- Pet booked and charged to Amex. Amex applied credits.
- When I cancelled ticket, only ticket part got cancelled, not pet charges, even though United.com said pet charges are being refunded.
- Called UA 1 week later, and refund for pet charges issued without any trouble.
- Amex has not clawed back credits after 1 week.
I suspect they will not since the refund and booking information is not the same for the pet charges. There is no ticket number or passenger name, origin, destination and even the reference numbers are not the same. So no way to link refund from UA to the original charge.
For example: when booked it shows up as
Additional Information: AAAA
WWW.UNITED.COMUNITED AIRLINES
Reference: 32018031081ZZZZZZZ
Category: Travel - Airline
Flight Details
DENVER INTL APT
HOUSTON INTERCONTI
Passenger Name: XXXX /INCABIN PET
Date of Departure: 06/06
Ticket Number: 016292051XXXXXXX
Document Type: ANIMAL TRANSPORTATION CHARGE
Refund looks like
Additional Information: YYYYYYY
WWW.UNITED.COMUNITED AIRLINES
Reference: 32018043XXXXXX
Category: Travel - Airline