We’re always glad to hear from MileagePlus® members like you. Thanks for writing.
I apologize you had difficulties using the MileagePlus X app. The MileagePlus app was experiencing an outage on October 5 and October 6. The pending charges on your credit card should not go through. If they do they will be refunded automatically.
We hope you us the MileagePlus X app for future purchases. Please let us know if you have any questions.