Lynn La/CNET

Sprint is eating everyone's dust.

The nation's third-largest wireless carrier by subscriber base sank to the bottom of a survey conducted by Consumer Reports over cell phone service. Sprint scored "dismal marks" in value, voice, text messaging, and 4G reliability, according to Consumer Reports' survey released Thursday. Sprint ranked No. 2 behind Verizon Wireless a year ago.

It's the latest headache for a carrier that is going through a long and painful transformation of its network. Sprint is in the middle of upgrading its network to allow for better and faster service, but the transition has been rough on customers. As a result, many have left the carrier in the last few years.

"While the findings in the Consumer Reports' survey are disappointing, they're not necessarily surprising," said a Sprint representative. "We've asked customers during the past year to 'pardon our dust' as we build out and upgrade our network."

Sprint is hoping the rate of customer attrition will fade once the network improves. To drum up interest for its next-generation network, the company last month demonstrated Sprint Spark, its enhanced LTE network. The company said in areas where the coverage has improved, the customer satisfaction has moved up accordingly.

Verizon Wireless was once again the top-rated carrier, though Verizon recently conceded that it was facing pressures in big cities such as New York and San Francisco.

AT&T and T-Mobile scored "ho-hum" results, Consumer Reports said, but AT&T was the lone carrier to get a top rating for 4G reliability.

AT&T has been making a lot of noise about offering both the fastest and most reliable network in the nation, while T-Mobile has quickly built out its 4G LTE network to pair with its HSPA+ network.

As with previous years, smaller carriers ranked higher, with niche provider Consumer Cellular scoring best in cell phone satisfaction despite running on the same network as AT&T.

The survey also found that many customers are overpaying for their data, with 38 percent of users surveyed using half or less than half of their monthly allotment. While AT&T and Verizon have capped their data plans, Sprint and T-Mobile still offer unlimited data plans.