Who's responsible when a delivery goes awry? That's been an issue for some luckless consumers at least since the days when Sears, Roebuck & Co. pioneered mail order a century ago, and likely for clients of the Pony Express before that. Recently, it has gained urgency from the growth of delivery-dependent Internet commerce. One day, it may even be an issue when Amazon's drones target the wrong front stoop for a package drop.

The key thing to remember is that delivery systems endure because, almost always, they work as promised. But just in time for the holidays, Philadelphian Ellen Zucker has a cautionary tale to share about what can happen when something goes wrong. She found that it can seem a Herculean task - or, as she puts it, David vs. Goliath - just to make things right.

In the end, Zucker basically solved her own problem, and wrapped it up with a bow for Consumer 14.0, so this is mostly her story. It begins earlier in the fall, when Verizon Wireless lured her with an offer she couldn't refuse: Trade in her dated iPhone for a brand-spanking-new iPhone 6 Plus.

Verizon said the device would arrive via FedEx before 8 p.m. Nov. 12 at her Castor Gardens home in Northeast Philly. That's when things went kablooie.

Zucker's home, I should note, is a place where she has never had problems with deliveries, even while away at her job working for the state. It's on a neat block of rowhouses with large front yards, patios, and plenty of places to stash packages. Still, with a phone that retails for more than $700, she didn't want to take any chances. So when FedEx texted at midday Nov. 12 to say her package had arrived, she decided to drive home during lunch. She arrived less than 90 minutes after the supposed delivery. But there was no package, no note - no sign at all of her phone.

When she contacted FedEx, she got a surprise no one would want to hear: The courier company said it had a "Proof of Delivery" document, which it said showed that the package had been delivered to her address - and that Zucker herself had signed for it.

I've talked to Zucker only a few times, but I'm inclined to rule out any notion that she has an evil clone who sneaks around while she's at work and likes to play Angry Birds on her phone. I'll also accept that the scrawl above the words Indirect Signature Required wasn't her signature. But she had a tough time convincing FedEx or Verizon of the same.

Zucker says she called the companies nearly every day for the next three weeks. FedEx kept pointing to the signature as obvious evidence that it had performed its role. Verizon, hearing the same story from FedEx, left her equally frustrated.

How did she eventually break through? Zucker reported the vanished phone to police, filed a fraud report with Verizon with evidence of her actual signature, and disputed the charge with American Express. But she suspects what mattered most was an e-mail to a Verizon regional president. A few days later, she got a call from someone in "executive relations."

Zucker eventually got credited for the money she had lost. Still, she wonders whether she was treated reasonably, and whether other consumers would simply give up and accept the loss.

They shouldn't, but they should probably expect a similar hassle. Zucker had the law on her side because she never actually took possession of the phone. But proving that is the rub. For instance, the helpful Verizon staffer also told her that if the case had played out differently, the company would have answered her Amex chargeback by adding the lost phone's cost to her monthly bill. To get her money back, she might have had to go to small-claims court.

And what about that strange term indirect signature? FedEx spokeswoman Connie Avery says it's a residential-only option that allows more flexibility - though perhaps also more risk. A neighbor or building manager can sign for your package, or you can leave a signed FedEx door tag to allow it to be left without anyone present. A better option may be asking that a package be diverted to your work or to a FedEx location for pickup, which you can even do while it's en route.

Of course, in Zucker's case, there's no telling who signed, or where her phone wound up. Her victory came from convincing Verizon that it had a problem with FedEx, not with her. And perhaps, as Zucker suspects, from Verizon's interest in keeping a longtime customer happy.

215-854-2776 @jeffgelles