The District's new pay-by-phone parking system is supposed to make parking easy. But every day about 25 drivers who use their phone to feed the meter are getting parking tickets by mistake.

Annandale resident Kristin Stone and her daughter found a ticket on their car last week, even after accidentally paying twice for the space outside Arena Stage. Customer service at ParkMobile, the company that runs the service, was unhelpful, they said.

"I was pretty upset. I was very frustrated," Stone said. "It wasn't working, and I thought they should make it right. If they want it to succeed in D.C., they should be taking all measures."

Stone's daughter Elizabeth said she's already received three tickets after paying by phone, two of which were dismissed after she appealed them.

Arlington resident Laura Howell was not so lucky. She received three tickets after paying by phone, none of which was dismissed after she fought them. She tries not to park in D.C. anymore, she said.

"The mobile payment system is flawed and should not be grounds to receive a ticket until all system issues are resolved," she told The Washington Examiner.

The Stones and Howell aren't alone.

The District Department of Transportation estimates that about 25 drivers are mistakenly ticketed every day because of glitches in the pay-by-phone system.

The system, implemented citywide in July, is supposed to update parking enforcement officers' hand-held devices as soon as a phone payment is made. But sometimes that data doesn't load immediately, DDOT spokesman John Lisle said, leading the officer to believe the driver didn't pay.

"There are times there is a delay," Lisle said, adding that the city is updating the pay-by-phone software to fix the glitches. "We're working to eliminate those problems, and if it does happen to somebody, they can [appeal] it to the Department of Motor Vehicles."

Despite the glitches, Lisle said less than 1 percent of all pay-by-phone customers end up with a ticket by mistake. The city handles 10,000 pay-by-phone transactions every day and has about 180,000 registered users.

"Overall," Lisle said, "the system is very successful."