Canadian Heating and Air Conditioning

I got Canadian Heating and Air Conditioning Inc. to put in a new gas furnace in my crib on December 1. The next day, December 2, my gas water heater and gas fireplace stopped working. I reckon when they were doing the installation, they must've turned off the gas for those two things. I gave Canadian Heating a ring and after waiting forever, one of their peeps finally called me back. They straight up said there's no way their installation messed up my gas appliances. They ain't taking full responsibility and won't send someone over to check what's up. Clearly, their customer service is trash and I made a mistake picking them. They obviously don't care about their work.