A few days ago I purchased a download of an album on Bandcamp (Lykaia by Soen, in lossless FLAC format). Shortly afterward, I noticed that there was another version of the album with a bonus track, for $0.99 more; but the bonus track was not available for individual purchase.
I contacted customer support and explained the situation. They indicated that it was the band's decision not to sell the bonus track ala carte, but reversed the charges on my initial purchase so I could buy the download again with the bonus track.
They didn't need to do that, and in doing so were implicitly trusting me to re-buy the other version, instead of just keeping the (now free) copy of the original download.
I was already a fan of Bandcamp since they sell lossless music downloads at reasonable prices. Now they get another thumbs up for good customer service.