I am in the business of producing radio commercials. I create and produce the music, and I do the all the voice-overs (announcing). I supply several vendors (telemarketing sales companies) with completed "ready-to-air" packages of radio spots, each containing anywhere from 1 to 12 spots. My arrangement (verbal) with all my vendors is that I am to be the exclusive voice-over (announcer) talent on any music beds (called "donut jingles") that are mine. I am paid per spot. In order to initiate sales, I have given several vendors free demonstration recordings to use as sales tools. One particular vendor on numerous occasions has asked for the music beds only to be included in the particular order at the buyer's request. Over a period of 9 years, I have probably supplied this vendor with over 150 music beds which I was led to believe were going directly to the buyer/end-user. I have recently learned that this particular vendor has been using my music beds to create and produce radio spots using his own voice in his private studio. He is selling these productions using my music beds and not informing me nor paying me. Upon examination of my sales records, I show a 40% drop in business over the last 24 months, and a sudden cessation of orders from long-time customers. I also have obtained two voice recordings with his voice over my music beds. What do I do?