McDonald's just can't climb out of the customer satisfaction cellar.

For the 20th year in a row, McDonald's ranks dead last in overall customer satisfaction in a national survey of of customers of 12 major fast-food chain customers by the American Customer Satisfaction Index.

Papa John's and Pizza Hut tied for first place -- where Papa John's has ranked for three consecutive years. Two other pizza chains, Domino's and Little Caesar's, tied for second place.

But following three years of improving its numbers, McDonald's customer satisfaction numbers fell back 2.7% compared to the year before to bring up the rear. The good news: McDonald's customer overall customer satisfaction numbers are up nearly 13% from where they were when the annual survey began 20 years ago.

"McDonald's has gone from being way lower than the nearest competitor to within striking distance of the rest of the industry," says Forrest Morgeson, director of research at ACSI. "The bottom is not where you want to be, but at least they're getting closer to the thick of things."

The survey of 4,572 customers, chosen at random and contacted via telephone and email, was done from January 13 to March 11. The survey does not cover smaller, fast-growing chains like Chipotle and Panera Bread.

McDonald's says it takes the survey results seriously. "We always listen to our customers and appreciate hearing feedback from them and other sources as it helps us improve and evolve," said spokeswoman Lisa McComb in a statement.

Why can't McDonald's break out from the back of the pack? "With size comes a much more diverse group of customers," says Morgeson. "As your customers get more diverse, it gets more difficult to satisfy them all."

Another reason: McDonald;s biggest fans typically are kids, not adults, and the satisfaction survey includes only adults 18 and up, notes Morgeson. "Remember, it's often the kids who insist on going to McDonald's."

Several other familiar chains took hits in the survey:

• Subway. The sandwich chain saw its satisfaction rankings slip 6%, to a tie for third place with Wendy's. Consumers showed concern about pricing at Subway, says Morgeson. Subway declined to comment.

• Starbucks. The coffee kingpin saw its satisfaction rankings fall 5% to a tie for fourth with Burger King. While consumers are pleased with Starbucks quality they are concerned about its pricing, says Morgeson. "Serving our customers is our top priority and we are always striving to exceed their expectations," said spokeswoman Linda Mills in a statement.

• KFC. The chicken chain took the biggest year-over-year fall of any chain in the 2014 survey -- down 8.6%. Customers are disappointed in both quality and pricing at KFC, says Morgeson. "When you drop that much, you have to pay attention." KFC says it is. In April, it rolled out a new customer service platform to gather more "meaningful and actionable feedback," said Jason Marker, general manager of KFC U.S., in a statement.