Just 15 banks and one credit union accounted for about 80% of consumer complaints to the CFPB about bank accounts or service, according to the agency's November complaint report.

Based on consumer complaints the CFPB sent to companies for response between June and August 2015, Bank of America took the top spot as the most complained-about financial institution, with a three-month average of 284 complaints. Wells Fargo was number two, with an average of 216 complaints, followed by JPMorgan Chase, PNC Bank, U.S. Bancorp, Citibank, SunTrust Bank, TD Bank, Capital One, Regions, BB&T Financial, RBS Citizens and USAA Savings.

The Vienna, Va.-based Navy Federal Credit Union came in at number 14, with an average of 26 complaints – a 54% increase versus the same three-month period in 2014. The credit union ranked third in terms of largest percent increase in complaints over last year, the CFPB said. PayPal ranked first (a 109% increase), followed by USAA Savings (also a 54% increase, but with slightly higher average monthly complaints). Navy Federal, which has $72 billion in assets and 5.9 million members, did not respond to a request for comment.