SWAT Environmental Air Quality Control Agency System Doesn't Work in Cold Weather - Design Needed Modification (Which They Charged Me For) Lansing, Michigan

I had a radon removal system installed on 1/18/13 and two days later the system quite working.  A service person came out and found the exhaust pipe totally plugged with ice.  They decided to modify the system to avoid this ice buildup and then presented me with a service charge of $249 (if I paid immediately it was only $149).  I refused to pay since their system design didn't work properly in normal Michigan temperatures.  They contend it is not their fault the temperature is cold in winter and I was responsible for the charge.  They eventually said they would take $149 and I paid just to avoid the hassle of dealing with their collections department.