AT&T has posted a statement regarding iPhone 4 availability at its retail stores on June 24th. In short, if you didn’t pre-order the iPhone 4, don’t expect to pick one up until next week at the earliest.

“AT&T is on-track to deliver iPhone 4 to customers who preordered the device on June 15. We look forward to offering iPhone 4 to all other customers beginning Tuesday, June 29, when it goes on sale in all AT&T sales channels,” reads the statement.

This contradicts information offered by some AT&T retail store employees to customers who inquired about the availability of the iPhone 4. At least some store locations expected to have a limited supply of stock on-hand to accommodate the first few walk-in customers. Now that appears to not be the case.

AT&T indicates that retail representatives will begin calling customers this week to let them know their iPhone 4 is available in the store for pickup. What’s more, at least some customers who ordered the device for home delivery are already receiving theirs.

Even on June 29th, though, AT&T cautions that stock will be “available on a first-come, first-served basis while supplies last.”

Last week Apple reported that more than 600,000 people had pre-ordered the iPhone 4, ten times the number that pre-ordered the iPhone 3GS, overwhelming AT&T and Apple’s ordering systems.