Devcon Security Horrible collections and unfair collections/contracts hollywood Florida

I encountered unfair and rude collection agents after when I installed a cell phone GPS system and paid the person in PERSON and yet Devcon had no record of it. Shortly after that I discovered the GPS system was installed incorrectly and was in fact NOT monitoring my home for over 9 months because the signals were being sent to the WRONG account #. After tons of collections calls from rude account managers I finally got some one to review my account and speak to a supervisor who acknowledged that my system in fact was not properly installed (or working) after having a person come to my house and inspect it. I requested a refund for all the quarters that they billed me for that the alarm was not working and all they refunded me was 7$ a month for the GPS system even though my entire alarm system was not communicating with Devcon because the wrong account # had been entered among installation! I wanted to cancel my service immediately. In June of 2013 collections sent me a letter threatening me that my acc was 10 DAYS PAST DUE and that they would cancel my contract. I thought great! Now in October they send me a bill for over 1,0000$ claiming they want the remainder of my contract because of cancellation. I don't recall being under contract, but I called the call center where a rep told me that my contract expired in 20010, but Devcon took it apon themselves to renew it and are now trying to charge me for a new contract through 2017. I told her that I have lived in this house for over 5 years and I had Devcon install my system w the builder. I was NEVER given a contract and over the last 2 years I have repeatedly requested to sever my business relationship w Devcon because of their horrible record keeping and collection services and NO ONE EVER MENTIONED A CONTRACT yet it was renewed without my consent! When I went online to view my account (when I got a bill for almost 4000.00$ Devcon erroneously debited my account 2 payments of 119.35 which I EVER AUTHORIZED. When I asked for a refund and there was a pending paymetnt on the acc the rep was more than willing to process it. When I found out Devcons customer service rep took a payment from my husband and misled him and NEVER verified the amount which was over 1,000 I cancelled it and told her I in NO way wanted to continue to do business with DEVCON. She then said they could not guarantee that they would refund the money that was debited from my account. YET she had just said it could be refunded!