A woman caring for her parents, both in their 80s, says the power company sent her a $10,000 bill and couldn't tell her why before shutting off the service the elderly couple relies on to power their oxygen tanks.

In what could have been a very dangerous situation, she says the surprise bill left them in a helpless situation.

After eight decades in California, Debra Andersen's parents moved to Wildomar to a property she owns, nearby her own.

“We moved here with the intention of them being able to live out the rest of their life and take care of them,” she says.

Relying on electricity for their oxygen tanks, they invested $50,000 in solar panels last year to lower their power bills.

It didn't save them very much. She says maybe a few hundred dollars for the year. Then came the surprise bill from Southern California Edison.

“If you could have a heart attack without having one, that's pretty much how I felt,” Debra says. “The (customer service) lady, you know, was very sympathetic and said ‘Yeah it doesn't make sense, but, you owe it.’”

That is certainly not money Debra has laying around.

“My mother's on oxygen, she's on 24/7. If they cut the power, she has no recourse but to move,” she told NBC4 days before the power was indeed cut.

The solar panels on the roof are now Andersen's sole source of electricity and her parents' lifeline.

“It makes me feel helpless,” she says.

The Better Business Bureau's Steve McFarland says most power companies have an ombudsman -- someone you can contact who can bring special circumstances to the company's attention.

“I would expect something like that would be resolved, especially for something that would be unjust enrichment for- for a large utility,” he says.

But SoCal Edison does not, and Andersen says customer service isn't helping with her mystery $10,000 bill.

“That would be something that they probably would not want to have go public,” McFarland says.

SoCal Edison would not give an interview to NBC4 and would not comment specifically on Andersen's situation, blaming privacy reasons.

They did issue this statement:

"Solar customers participating in the NEM program are billed for their energy usage on a yearly basis. That is why SCE diligently informs customers who install solar panels and participate in NEM to review their bill and usage each month throughout their annual billing period to avoid being surprised at receiving a lump sum charge. They receive what’s called a "true-up" bill that totals all energy (kWh) charges and credits. At that time customers are responsible for paying any energy charges accumulated over their 12-month billing period that were not offset by energy credits."

The company insists "The bill in question is correct."

Andersen says the company agreed to turn her power back on only if she paid $900 and went on a payment plan.

Feeling cornered, Debra says she has no choice but to pay, whether or not she knows what the charges are for.

“Well, everybody says the same thing, ‘there's no way you - you shouldn't have to pay it; it doesn't make any sense.’”