I recently called to change a non-refundable ticket on CO and was told there was a $100 change fee, and when they repriced the fare it came out $44 higher, so was expecting to pay $144 in addition to the $189.50 I'd already paid. I gave the res agent my credit card number, and on my receipt which I picked up at the airport, it shows a total of $233.50 and a second amount of $44 (with taxes) in addition to the $189.50 already paid (i.e. 2 line items on the receipt).

Where does the $100 usually show up? Should my receipt have shown $333.50 if it were charged? I also can't find the $100 charge to my credit card, which leads me to believe they may have overlooked the $100 change fee (or waived it or whatever). This was the first ticket I've ever tried to change, so I don't know where to expect the $100 to show up.....