Out of seven major U.S. credit card issuers, Capital One drew the greatest number of complaints from its customers in 2012, according to an analysis of newly public complaint figures released by the Consumer Financial Protection Bureau. Creditcards.com found that American Express generated the fewest complaints by purchase volume of the seven companies, but it also was least generous in terms of credits and other kinds of payback after receiving a gripe. The agency's detailed records provide a first-ever look at disputes between card issuers and their customers -- with billing disputes, interest rate problems, and credit report complaints coming in at the top -- as well as which companies are likely to pay back a customer who experiences a problem. A separate poll by J.D. Power, meanwhile, calculated that 11 percent of all account holders encountered some kind of issue with their credit card last year, suggesting that the 15,000 or so grievances submitted to the CFPB in 2012 is a strong underrepresentation of the actual level of customer dissatisfaction. However, J.D. Power notes that the 11 percent complaint rate is down from 18 percent in 2009, before the Credit Card Act took effect in 2010.