Is it illegal for a middle man company between a tenant and a landlord to sign an agreement relating to the house itself?

I am renting a house through a business we can call them company "A". Company "A" used another company, Company "B", who is a realtor group to "get the name out" and have more people look at their houses. When I viewed the home company B showed it to us and told us that everything we needed to be fixed would be. I had company B sign an agreement that listed everything that needed to be fixed. Now 4 months later nothing has been fixed (broken windows, doors that don't shut etc.) and company A says that although they will fix it they did not know until now about it. Our heating bill for the last 4 months is well over 1,000 dollars because nothing has been done to fix the windows and door. Do we have a case to make them pay our heating bill?