My account was debited (Tuesday) so I sent a refund request and an email to MP. We'll see....

Here's UA's response:

Dear XXXXXXX:

Thank you for your email.

Please accept my apologies for the inconvenience and frustration you experienced resulting from your delayed flight.

After reviewing our standby policy, I found that our agent mistakenly charged you. A fee of $50 is collected when a customer successfully boards another flight. However, the fee is waived during irregular operations or involuntary standby.

My regret is that not only were you a victim of a schedule change but we failed to properly follow rules and policies. I am truly sorry we failed to do our part.

We will gladly honor your request for a refund of $50 and in addition have issued you $200 E-Certificate as a goodwill gesture. I understand that our goodwill offering can not compensate you for the inconvenience of having to adjust and alter your plans at such short notice. Nonetheless, we would like to provide it as a tangible expression of our regret over what transpired and our gratitude for your loyalty with United Airlines for nearly 14 years.

We look forward to serving you again XXXXXX.

At the conclusion of this email, please fill out the survey where you can rate your experience with the Customer Care department. We value your feedback and hope that you are satisfied with our service.

Regards,

XXXXXXX
United Airlines Customer Relations


Props to UA for the quick response and making things rights. I may have to keep a copy of my email and UA's response with me when I travel as I'm sure this could easily happen again.