Paula- Yes, you probably have a cause of action. The problem the remedy will be limited to your damages. Your damages will be the late fees that were charged. As a result it would most likely cost you more in legal fees then what it is worth.
Your second option is to send them a Qualified Written Request (QWR). RESPA is the federal statute that governs these sorts of things. A RESPA QWR has the force of law and you can do it yourself.