Water Works Unlimited

I have annual maintenance contract with Water Works. There was leakage in my back-flow. I contacted them to check. And my nightmare starts from there. They gave me an appointment for a time. But they never turned up. I had to email them and call them time and again. But no response. Finally they get back and gave me another appointment. No one turned up this time either. And the same cycle of follow ups continued. After, constant follow ups finally someone turned up. The guy came in and started talking very rudely, for no reason, I was shocked. He said that they need $250 for fixing it. Which I agreed. But he said very rudely that first I have to give them check then only they will start the work. I came back with check for $250. Now, this time he says that $250 is not sufficient. They want $350. Being helpless, I ended up giving check for $350, hoping that my nightmare will end here.
Couple of months later my back-flow started leaking again. And the same cycle of followups continued again. Finally the same guy showed up. This time again he was utterly rude right from the moment he came in. The very first thing he did was, very rudely demanded check for $250, He said that unless he gets check for $250 he will not even look at the back flow. He requested him gently as to why he should charge me again for the same problem for which I have already paid. At that he started yelling at me. I tried to calm him down. Being helpless, agreed to pay another $250. Then he again yelled at me to bring the check first. To that too I agreed. And I requested him to not be rude. At that he got very angry and said that he is partner of the company, used racial slurs and threatened me. I was shocked, completely helpless, was considering calling cops. And then all on sudden he sat in his truck and started yelling, threatening with dire consequences and drove away.
Now I don't know what I should do.

In May, I sent Waterworks a check for a backflow meter check. Before the work was done I cancelled the request and asked that my check be returned to me. Instead the check was cashed and I have written to them in September and again in November and still have not received a refund.