Business ProfileforState Line Propane LLC

I have a ductless heating and cooling system which is not working. I saw an ad in TV by State line oil company that they service ductless heating and cooling system. I called thier service number and I scheduled for a technician to come out and 'fix' the system. They took my credit card information and stated that they will charge by the hourly rate for the technician to come out and service the system. The technician from state line oil came to our house and looked at the system from outside the house. He never entered the house or did any detailed technical analysis. He spent about 10 minutes saying how bad the system was. He said 'it will take two of his men a couple of hours' to fix this and they will have to change the entire ducting on the outside. He left in about 15 minutes. He did not fix anything and never gave any written estimate for the job. My credit card was billed 300$ for this visit. When I called the company they explained that it was 1.5 hours of technician time plus tarvel time. I disputed this charge and they said they can do nothing about it. I talked to the service manager who looked at the 'technicians note' from that visit and could not gather anything useful and said he will 'look into' it and get back to me. Since then I have made atleastr 15 phone calls and left messages but no answer. Here are my issues: 1. I was expecting the technician to come and fix the proble, this was not an 'estimate' call. and if they do that then they should have told me that I will be charged just for the estimate. 2. I dont think I got any realistic estimate of the work needed. saying that it will take couple of hours is not an estimate for which you charge somebody 300$. 3. I don't think the company has the expertise or capacity to actually service this system.So, why are they coming out for an 'estimate' and charging me when they cannot actually take care of the problem. I even told them to do the job, but they are not doing it. so why the estimate??