I would send them an Intent to Sue letter first unless they stopped reporting their tradelines on my reports. If they refused, the I would bring my own legal action against the CA for $1,000 for each offense plus any other damage I suffered as a result of their violation. I would file complaints with the BBB and FTC as well but those would probably not be my main focus or leverage...
Starting Score: EQ 575 EX 595 TR 524