Xcel Energy, Excel Energy They won't turn on my electric Amarillo Texas

Me and my family moved in to our house September 1, 2008 we called xcel energy to transfer the electric from my sister in-laws name into my fiance' name .I explained that his sister had moved out and we moved in, and she left owing Xcel money. they told me that her bill needed to be paid. I told them that she didn't live there anymore. they asked if we had a lease or rental agreement. we drew up a document with his mother on our personal agreement and faxed it to them. they decided that they were not going to turn on our electric until she pays her bill which is part from this house and part from another it is $644.?? we cannot afford to pay that.

They have investigated. we have tried everything we can think of she won't pay the bill. I offered to pay what she owed on this house and they still refuse to turn it on. we have been living by candle lite since this has all happened. I don't what else to do I have tried everything I can to fix this and they just keep telling me its my responsability to pay her bill.

I have left messages for the investigator to call me 4 different times over all this times and I never get a call back. They keep telling me that they refuse to turn on electric until her bill is paid. If anybody has any Ideas let me know

Regina
Pampa, Texas
U.S.A.