In early November, I booked a trip from PDX to SIN, departing in late January. Although I reserved the flight for $570, I was quite surprised to see an amount of $615 appear on my Visa Statement when it arrived earlier this week. I immediately called web technical support at 1-800-589-5582 but they initially insisted all they could see was the $615 fare. When I pointed out that I had actually saved my confirmation screen in PDF format, all of a sudden they were able to find evidence of my original fare by looking at the history of the PNR.
Even this was not quite sufficient to dispute the charge, so I was asked to email the file to them. They pointed out that simply forwarding the confirmation email itself was not really adequate because anyone could alter an email. I thought to myself that anyone could alter HTML too, but so be it.
All that this really accomplished was for them to
start in investigation. After giving them a week to investigate, I called back today to inquire about the status of the investigation and was told somewhat curtly that it was in the hands of "Ecommerce" and there was nothing further the web site folks would do or say about it.
At that point, I escalated the matter to a supervisor, who quickly confirmed that they would be refunding me the difference, as I had requested. Actually, the way they are handling it is to credit the entire amount of $615 and then debiti the $570. Fine with me if that's the way they want to do it.
I asked the supervisor how something like this occurred so I could avoid a similar situation in the future and she responded by explaining how complicated technology can be sometimes.

I remember thinking to myself what would happen should I ever say that to one of my clients; I bet they would most assuredly become my
former clients very quickly.
But I told the supervisor that I really do understand how difficult technology can be for the ual.com web team. I explained that I figured this out because of all of the problems I have encountered with active itineraries and the E-Upgrade summary over the past many months.
In any case, the bottom line is that if I didn't have reasonable proof about the original fare, I would have had very little ammunition to dispute the erroneous charge. None of this should really be necessary with a well designed web site and proficient customer service team but that's the sad reality in the rarified atmosphere of ual.com.