This is the best way to mess with an Apple Store employee.

Apple tells it's new recruits exactly what to think and say. It’s all in their Genius Training Manual.

It's a penetrating look inside Apple: Psychological mastery, banned words, roleplaying—you've never seen anything like it.

Apple tries to make sure that it's employees offer the best service possible to their customers, especially since they’re the ones that have made this company so rich.

One of Apple’s strong policies is that THE CUSTOMER IS ALWAYS RIGHT. Therefore, they might sometimes encounter people who are not that related to Apple products and that mispronounce the name of their products.

In case they have to deal with a customer that pronounces the names of products wrong, employees are not allowed to correct them. If you want to irritate an employee, go try mispronouncing one of their products as bad as you can.

(Source)