As a follow up, screenshot of part of credit card current charges statement showing new E-ticket numbers generated by UA for ancillary charges (in this case, an upgrade co-pay). Both are different than E-ticket number on itinerary (which stays the same) to which these were applied. Should be able to get some sort of receipt based on researching the E-ticket number corresponding to the OP's $125 charge. The difference between my case and OP's is that both $550 charges showed up on my updated current itinerary receipt (which led me to look at charge card listing)
UA managed to charge me twice for my upgrade to PF LHR-SFO. Took only 30 seconds for agent to see the error and reverse.
Last edited by IAH-OIL-TRASH; Sep 3, 2017 at 4:24 pm