What can I do about getting monies returned from a company that took a deposit and when terminated did not return the deposit?

I hired a fence company to replace a fence on my property after the hurricane. They asked for a $3000.00 deposit.. After giving them the deposit I was given excuses about them starting the job. When I said I was going to cancel if the job wasn't started they began. I came home from work to find irrate neighbors who informed me they went 4ft onto their property. It was clear that this company did not know what they were doing. They did not follow property lines . Put up posts incorrectly . I told them to desist and pick up their material and return my deposit. They refused and kept the deposit. I have sent them letters and they refuse to respond. I hired another company and had to pay again and they gave me a letter stating that the job they saw was totally unprofessional. What can I do