Since John Legere took control of T-Mobile in 2012, the carrier has orchestrated a remarkable turn-around. Through launching the Un-Carrier initiative, T-Mobile turned its scrappy underdog status into a marketing plug, and by adding the iPhone to its lineup and investing heavily in network infrastructure, the company’s product is now on par with AT&T and Verizon.

But the most under-appreciated aspect of the turn-around is T-Mobile’s customer service. Things still aren’t perfect by any means, but T-Mobile’s focus on customer care has had a measurable impact, resulting today in the highest-ever score on JD Power’s wireless customer service survey.

T-Mobile and its prepaid subsidiary, MetroPCS, each scored the highest-ever total score in their respective categories. That’s an impressive achivement; it’s even more impressive when you consider that five years ago, T-Mobile lagged behind the competition and wasn’t even in first place overall.

“Our incredible customer care teams at T-Mobile and MetroPCS just made history with their customer obsession, and because we’re the Un-carrier, we won’t stop at just being the best in wireless,” said John Legere, president and CEO of T-Mobile. “We’re primed to go totally next level in 2018!”

Since starting the Un-Carrier movement, T-Mobile has rebranded its customer care team as “T-Force,” and put emphasis on non-traditional customer care options like live chat support and social media direct messaging. It’s still not a perfect system — T-Mobile’s billing and control software still causes problems for the reps themselves, which leads to billing errors on occasion — but on basic metrics like wait time and problem resolution, T-Mobile has really turned things around.

Chris Mills has loved tinkering with technology ever since he worked out how to defeat the parental controls on his parents' internet. He's blogged his way through Apple events and SpaceX launches ever since, and still keeps a bizarre fondness for the Palm Pre.