I recently stayed in a Hyatt hotel that offered Diamond members breakfast in the restaurant. Every Hyatt hotel is different – some will have buffets and at others you just order off the menu. Normally, you can order any one entree and beverage and the hotel will deduct the entire check (including tip) from your stay invoice.
Thankfully because I regularly scan and lightly reconcile my credit card statements via mint.com, I found the unusual charge and called in to inquire. The hotel apologized for forgetting to remove the charge and removed it from the invoice.
Monthly credit card reconciliation is a good practice to have to catch these discrepancies. It helps you to ensure that you are receiving the full value your elite status benefits, since many benefits are manually adjusted and mistakes can happen. If applicable for you, I also recommend doing this with your significant other as part of a healthy relationship, so you can have conversations about money and work towards alignment. You can adjust the frequency to meet your needs and spending patterns. I normally reconcile at least once a quarter (or after a significant cycle of cc applications).
What is the most surprising travel expense discrepancy you have caught?