I just switched to a new advertising system on my forum that allows anyone to buy advertising space after my approval. One guy bought ~$25 worth of advertising to advertise his free ebook on the topic of the website. Eventually, he started charging people for this ebook, just over $25 each. One of my forum members came to me saying that the ebook is completely useless, and actually contains pictures that he copied from my forum. Needless to say, I paused his ads, and he is demanding a refund. I told him that we need to investigate since he ripped off images from my site. Who thinks I should give him a refund?
If that is in fact what he did, i would not issue a refund, and maybe out of your control also depending if he disputes the charge with his payment processor... whhat sorta forum do you have? what is the URL?
Personally I would give a refund. Sometimes people can cause you more trouble than that refund would have been. In my business I make it policy to refund customers simply because it is good business. I have found this has also helped my business as well.