Well John, I think you were quite lucky really. When I tried to purchase some miles via the "Mileage Accellerator" option in my award booking, the website errored out and asked me to call United web support. I was then able to purchase the miles over the phone. When I checked my bank statement a little later, I noticed that I had been charged twice for the miles (and both charges were confirmed, not pending). So I rang United again and asked them to cancel one of the charges. The response was that they could only see one charge in their system, so they weren't prepared to do anything, even though I sent them a screen dump from my booking showing receipts for two payments but with only one set of miles credited. I was told the only thing I could do was to dispute the charges with my bank (and they even sent me an email with this advice!). What a comedy of errors. I'd advise anyone making a payment via united.com to thoroughly check their bank statement and not to try again if an error is received when making a payment online.