Incompetent Security Company

Worst experience ever. I signed a contact with the salesman/rep with a promise of a security system to be installed the next day. I paid the deposit to the salesman/rep. The next day when I queried as to how late they would come and install, I was told they only put in the order that day and it could take up to 3 days. I went in after numerous phone calls and told them I wanted to cancel and I wanted my deposit back. The man that took my money the previous day said sorry but he didn't have it as he had deposited it into the company account. I was told I would have to wait for it to be paid and cleared in my bank account. I did get the deposit back and that was the last I heard from them, until today. I received a message from a collection agency saying I owe them over R3000. How the ......? Then try and contact their accounts department or manager. They do not answer their phones nor do they bother to call back. I would NEVER recommend them to anyone. They are incompetent and inconsiderate.