I'VE GOT a shocking story for you. Not one shock, but several - some good, some not.

The first shock - a $12,169 gas bill from PGW - electrified Robyn Irving, a data coordinator at Children's Hospital of Philadelphia.

She got the insane bill for her two-story Nicetown rowhouse in July, a month after PGW fixed a leak in her gas meter. Twelve thousand freaking dollars? Was PGW pumping Chanel No. 5 into her home?

Irving, 58, complained, but PGW was slow to provide an explanation and, ultimately, no satisfaction, she says.

Distraught, she told me her story and I looked into it.

The second shock, this time mine, came in a chat with PGW Senior VP of Marketing and Corporate Communications Doug Oliver, who admitted that PGW had made a mistake. The $12K bill was a "a clerical error," he says. No one was disciplined because it was an "honest mistake."

A big utility admitting a mistake? Shocking.

It was a very long-standing clerical error that allowed charges to build up over a decade, even though Irving dutifully paid every bill PGW sent her, Oliver concedes. The problem was that PGW billed Irving only about half of what it should have.

The type of malfunction struck about 35 of PGW's 560,000 meters last year, says Oliver, for a 0.0007 error rate. That's excellent - unless you are one of the 35.

The third shock was that even though the huge mistake was PGW's, it won't completely wipe the debt from its books. PGW did knock the $12,169 down to $4,433.45 - but that wasn't exactly voluntary.

The PUC prohibits reaching back more than four years to collect bills. That's the fourth shock, a good one.

The fifth shock, a small one, is that despite its admitted culpability, PGW wants the remaining $4,433.45 from Irving.

If PGW doesn't collect the money, Oliver says, "it would be 'bad debt' for PGW and it would be subsidized by the rest of the customers" because "we don't eat the cost. Everyone else must eat the cost."

"Everyone else" means other PGW customers. You.

This is where it gets delicious.

If PGW, as a gesture of contrition, were to clear Irving of the debt for the gas she did actually use, you would be paying that bill - creating a new injustice to rectify an old one. To resolve issues like this we usually turn to philosophy or religion, to discuss the nature of good and evil, fairness and the common good.

Irving was unhappy holding the bag for $4,433.45. After I started poking around, Irving says that PGW wrote off about $800 in late fees - which never should have been applied - bringing Irving's debt down to $3,575.37.

"It's the gas company's fault the meter was malfunctioning. When a meter is scanned, that's what's billed" and that's what she paid, says Irving, who also feels that insult was added to injury when no one from PGW called her to apologize for the mistake.

With its mistake admitted, PGW is offering Irving a plan to spread the payments for the $3,575.37 over four years, the same period of time it took for the debt to accrue.

That is a good thing to do, but - since Oliver says that this type of mistake is so rare - a better thing to do would be to cut Irving's remaining bill in half.

That, in addition to a formal apology that Oliver tells me is coming, would show true contrition.

Email stubyko@phillynews.com or call 215-854-5977. See Stu on Facebook. For recent columns: