called to have my other suppliers tank changed out to Heritage never heard from them, called 3 times

So fed up with this company! Last year I couldn't go a month without getting bills where they had come to top off the tank & this year they have let us run out. I go in to prepay for gas & asked them to fill the tank & get a "call us if it gets below 30%" So I've got to check my tank weekly even though you can see my percentage from your office? Call for gas yet we now have no gas. It's freaking cold & their disclaimer states it's my responsibility to check the tank? What about their responsibility to do their job. I will be looking for another source.