My rights for my purchased broadcast time

[newtunes]

I bought radio airtime from a local radio station and do a weekly radio broadcast that I pay for quaterly. Every Saturday for an entire month, during election time a couple of political ads were run during my broadcast. I feel like my rights have been violated because, I paid for the airtime and I'm certain they paid also for time that was mine. Isn't this illegal to sell something that doesn't belong to you. What recourse do I have as a customer of this radio station? who do I go to for help with this?