How Can Pg&e Let A Electric Bill Climb To Over 2300.00 Past Due On Low Income?

In 2009 my daughter and her family (2 adults, 2 children ages 7 & 20 mos.) moved into a home along with her husbands brother's family (2 adults, 2 children ages 7 & 20 mos.)  The PG&E is in her sister-in-laws name, and each month my daughter gave her payment for their 1/2 of the utility bill.  She did this in GOOD FAITH that the PG&E bill was being paid. Last week her sister -in-laws family moved into a home provided to them by the new company the brother-in-law now works for that includes utilities.  Well now PG&E has shut of the power, and will not transfer the service into my daughter's name because there is an outstanding balance of over 2300.00!!  Apparently the sister -in-law signed up for a low income plan with PG&E, was only making payments when she would get a dis connect notice!!  No one knew the sister-in-law was doing this..not even her husband. PG&E refuses to turn the power on and transfer it into my daughters name because all of them were living together and they are not "new tenants"!  It is cold, her and her husband both work and have 2 young children, and PG&E doesn't care!  How can PG&E let a bill climb so high especially if the person is on a low income payment plan?  If a low income person can't pay the monthly bill, how can they come up with 2300.00?  Not only has the sister-in-law caused my daughter's family to suffer, she purposely didn't pay the bill, and PG&E allowed this to go on.  My daughter and her family have come to stay with us, which means a daily commute of 60 miles. We live in a small mobile home in a 55 & over park. They cannot afford to move right now, it is Christmas, and the middle of winter.  Is there ANYTHING that can be done NOW to get their power on? Is right they are suffering so?