I arrived for a blue club membership no cool call. I first spoke with the customer and he was complaining that we did not come out for our yearly service on time and now his system is not running. I explained that I cannot see if we tried to reach out and we could not get ahold of him and that I would have to check with the shop Monday to see what happened. The customer is upset that the new heatpump that he purchased is not running. I inspected the system and found his drain line that was installed in January of 2013 is stopped up and overflowed into his secondary drain pan and this was keeping the system from running. I tried to explain that the drain safety switch dose not cause the drain line to stop up and that it keeps the system from making more water and overflowing into the ceiling. The customer is mad and upset and extremely rude would not let me talk and he would over talk while I tried to explain the issue. The customer walked off and I did not engage with the customer at t