An Atlanta law firm that landed more than $100 million in settlements against credit card processing firms over merchants’ billing complaints filed a new proposed class action in Cobb County Superior Court, claiming that Alpharetta, Georgia-based Priority Payment Systems routinely overbilled its customers and charged hidden fees.

If merchants were to try to fire the company, they would allegedly be hit with hefty termination fees of several hundred dollars, according to the complaint filed by Webb, Klase & Lemond partners E. Adam Webb, Matthew Klase and G. Franklin Lemond Jr.