It is strange that company that sent the bill should be able to say who is to pay the bill. Do you rent this place you live in? Then is it in your lease to pay the utility or is it included with the rent? Is your name on the bill or someone else? How long have you lived there? Can your landlord tell you who is responsible to pay the bill?
I hope this helps you. If you do not get any responses then take it to the landlord or if he does not respond then ask medicaid or welfare what ever it is called in your state. If you live in town go to townhall or borough building to find out.Or county assistance office. I wish you good luck with this because you need heat for the winter.

I'm not sure if this works in the UK, but in us I was able to get help with my utilities though salvation army.