Had a UA $25 baggage fee in Aug. Waited till last week and still haven't seen credit. Then after checking the T&C I found that it states that "you must contact J.P.Morgan Priority Services at the number on the back of your Ritz-Carlton Rewards Credit Card within 4 billing cycles of the purchase date ". So I sent a secure message to Chase CS, and within 3 days, got the credit.

This is the major difference between Amex Plat airline credit. Also, you don't need to pre-assign which airline to be credit to.