On the plus side, they had plenty of fresh air all this time. But nobody is going ot reemburse his for the $$$ in extra utility bills and overall hassle. That's why we commonly say that a warrant, mfg, or a home warranty, is only as good as the company doing the work. More often than not, its a worthless piece of paper. IF a company isnstalls it right in the first place, problems are very, very uncommon. When there are, that are so rare for good companies, that they jump on it quick to protect their reputation.
Glade you got it fixed. I find this problem on a lot of service calls. The duct system apart in places. Some one has been in the attic, stepped on the duct work and never told anyone about it.