i have a friend who joined a particular big program's site years ago, not really for the site so much as that they advertised a particular plugin (he didn't know it was a plugin but he saw his favorite girls on the tour).

he joined the site and the plugin was down. he called me on the phone, knowing i worked on the web and i figured out it was a plugin and suggested he wait a bit and try it again. he surfed the rest of the site, but not all that enthusiastically as he had seen most of the stuff before. then, after an hour, he tried the link again and it still didn't answer. when he tried again the next morning, the plugin still wasn't up and he called and asked for a refund.

he was told he had spent time in the site. he tried to explain that his only real interest had been in those girls but did not receive a refund and was not treated very courteously, so he charged back based on the fact that the only thing he was interested in the site was not available.

i thought he was justified. i know how much interest he had in the girls shown on that one page of the tour and how little he had in the rest of what was there - mostly old ounique content he had seen dozens of times. while most webmasters i know feel a chargeback is always the member's fault, i think it depends.