Cosmopolitan Heating And Cooling Services

I have been a customer of Cosmopolitan Heating for over 10 years. For the past couple of years I am having all sorts of problems with the Furnace for which I still had Warranty. They initially replaced the heater core, only to have problems with it right after the replacement. Since then I am constantly having issues with the furnace, they never really fixed it and Cosmopolitan is asking me to pay a service fee for every time they are coming to look at it - even though they never had it working properly since they replaced the core.