If you invest, you might have a run-in, a complaint, or a dispute with your broker. If you decide to fight them, here's a cautionary tale - and it's not pretty.

Mark Mensack, independent fiduciary consultant and founder of Prudent Champion, went into a years-long arbitration with his former employer Morgan Stanley after blowing the whistle on hidden fees he thought customers shouldn't pay.

Most customer-broker disputes don't go through a civil court. Your only option is arbitration through FINRA (Financial Industry Regulatory Authority). In the last round, the FINRA arbitration panel lost hours of Mensack's testimony in his hearing. FINRA ruled against him and he lost.

"Go to arbitration in hope, but don't expect to win. It's not a fair process," says Mensack, who now runs a Cherry Hill-based 401(k) consulting firm helping companies pick the right plan without getting ripped off by hidden fees.

FINRA is a self-regulatory organization with the power and responsibility to supervise broker-dealers and brokers, according to Stuart Berkowitz, a securities lawyer representing customers.

"What do the public arbitrators look like? Many of them are lawyers who either are employed by firms that represent brokerages, want to represent brokerages, or do primarily defense work. Nonlawyers are predominately from the corporate world, conservative and often retired," he notes.

"What are the results? Less than 50 percent of customers receive anything and if there is any award there is usually just a few cents on a dollar," he adds.

In Mensack's case against Morgan Stanley, the insult of losing against the Wall Street firm was added to the injury of FINRA case administrator Arthur Baumgartner's claiming he lost a good portion of the audio recording. Turned out, it wasn't his first time misplacing evidence.

"Only after filing a FINRA ombudsman complaint did he tell me on the phone that the missing eight hours was never recorded due to human or mechanical error," Mensack says. It turned out that this same case administrator, Baumgartner, worked on a Massachusetts case initiated in 2008 in which records also went missing, according to the Massachusetts Lawyers Weekly.

So, be wary of fighting your broker, and prepare yourself; you may end up in kangaroo court.