Dallas converted 4,000-plus parking meters into pay-by-phone devices in September 2013. Thanks to a company straightforwardly named PayByPhone, all you needed to take part in this new convenience was a smartphone and a credit card.

Matt Sommer first noticed this last year, when he drove in from Plano to a business meeting in downtown Dallas. After spotting a green sticker advertising the new feature, Sommer—a self-proclaimed tech guy—quickly downloaded the app, plugged in his information, and headed for the nearby Omni Hotel. But he discovered PayByPhone is not a perfect system. Long before the meter was set to expire, he had a ticket on his windshield.

What happened? Parkers must input their license plate and meter location number by hand. Since the meter cannot update remotely, it continues to flash “expired.” Officers must then manually input the location number into a hand-held device and check the license plate to determine whether someone is parked illegally or just using the app. A small typing mistake on either end—the parker or the parking enforcement officer—can lead to a giant headache.

After getting the ticket, Sommer called both PayByPhone and the Dallas Police Department. PayByPhone said citations were the city’s business and gave him a follow-up number (that was disconnected). DPD, at first, said an officer error was impossible. He would still be responsible for the fine.

Sommer got off easy: he was eventually informed via email that his citation was dismissed. But his is just one variation of a PayByPhone horror story, most of which seem to share the same endless spiral into bureaucratic pits of hell. Contacting the city directly doesn’t solve the problem. Even if the city finds that the ticket was issued erroneously, the onus is still on the parker to contest the ticket within the 15-day window indicated on the citation. You can chance it by doing it by mail, but the city won’t reach a decision before the in-person hearing date, which is when the fine starts to skyrocket. Suddenly, the original $35 ticket doesn’t seem like such a steep price to pay.

It isn’t always a mistake on the officer’s part. Bill Sparrow, PayByPhone’s customer service manager for North America, says most of the complaints he’s investigated were the result of a parker error. Also, the numbers aren’t as high as you might think. From March 2014 to May 2015, there were 333,164 PayByPhone transactions made in the city; only 1,612 of those generated a ticket that was dismissed. That’s less than .5 percent. (The city does not keep a record of the number of tickets issued to parkers who used the PayByPhone app, only the number of parking tickets written overall.)

But how many wrongly ticketed parkers decide to formally contest? What the numbers don’t show is the frustration of trying to fix a simple mistake. Donzell Gipson, an assistant director for the Dallas Police Department, says that the city—which collects $4.5 million annually from parking tickets—is working to make the process smoother. By the end of the summer, the PayByPhone hand-held devices should be upgraded with a few fail-safes that prompt the officer to double-check information when discrepancies are detected. Gipson is confident that the technology is still an improvement over carrying a roll of quarters. Plus, he touts the safety benefits—the switch from standing on the street, fishing through your wallet, to sitting in your car, phone in hand.

Sommer is taking other precautions. Now when he uses PayByPhone, he leaves a note to alert the officer.