It means he charged the payment to his credit card, I got the money, and then he called his credit card company and canceled the charge. It's called a "chargeback" and people who do it are the lowest of the low.
Have you ever considered using paypal to accept payments? Some people like to buy memberships with their paypal accounts. I have been in business on the Internet for 3 and a half years and all I ever used to accept money was paypal and as of yet I have had no problems. The paypal account is free for you, however they charge a small fee for each transaction, which I think, is reasonable low to be honest! They also do out of country transactions again which is reasonable low! They accept credit cards, checks, and people can pay you directly out of their paypal account. Again I have accepted all 3 types of payments with no problems.
What is the point of posting this public? I believe this should be a private business transaction, and public humiliation will do little good. Especially if you are able to revoke the account access back to normal anyway. Not taking the side of the alleged crook, but I just believe posting it public is unprofessional, and does not do much except try to attempt to turn all the paying members against this "bad guy" which comes off as childish. Kinda of like screaming "He didn't pay! bash him everyone!"