I tried to buy a ticket DEN to SFO on the app. Got all the way to the end and then it errored out. Tried again, same thing. Switched to the browser. I got to the end there and got a pink banner at the very end (after clicking to pay): "We are unable to process your request. Please try again later." Now I see TWO charges from United posted to my Chase card. Do I need to call Customer Service for this or just see if I can cancel one of them tomorrow from the app? (No status, if that matters.)