Monitronics Contract Scam! Internet, Internet

I  signed a 39 month contract for security services with Pinnacle Security on August 9, 2008. That contract was fulfilled in full on schedule, despite changing hands to various other companies more than once. Monitronics was the last company holding the contract. Not being happy at the high monthly fee we were being charged, my husband called Monitronics and asked for a lower rate. They did give us a slightly lower rate, but not one we were particularly happy with. We continued to pay them, but when we had an opportunity to do business with a different company, my husband called Monitronics on 5/15/2012 to cancel their service. They insisted we were under a contract and told us we had to pay them $348.98. I HAVE NEVER SIGNED A SECOND CONTRACT AND HAVE NEVER RECEIVED ANY NOTIFICATION OF A CONTRACT EXTENSION AGREEMENT IN THE MAIL. When the original contract was signed, I was led to believe that once my initial obligation was over we would be free to drop their service if we so chose. They have proven to be scam artists and have stolen my money and I want it back! I was aghast to see how many similar complaints have been made about this company's practices.