According to a new study, Apple Pay has seen high adoption among users in its first few months, though many users report disappointment with the in-store experience.

Apple Pay, has seen a wide acceptance rate among customers, with 66% of iPhone 6 and iPhone 6 Plus owners adding at least one card to the payment service, according to a new survey. However, many customers are reporting disappointment when it comes to using Apple Pay in stores, in part due to inconsistent implementations of Apple Pay by merchants.

From Phoenix Marketing International:

"The demand is there: 59% of Apple Pay users have gone into a store and asked to make a purchase with Apple Pay. But so is the disappointment: 47% visited a store that was listed as an Apple Pay merchant only to find out that the specific store they visited did not accept (or were not ready to accept) Apple Pay."

When they do find a store that supports Apple Pay, many customers run into problems during checkout. Several respondents to the survey reported that payment terminals often worked slowly, and cashiers were ill-equipped to aid customers that needed help using the system.

Apple Pay first debuted in October 2014 for iPhone 6 and 6 Plus in the U.S. The payment service now has the support of 2,500 participating banks, along with 700,000 businesses.

Source: Phoenix Marketing International