At first it looks like any other receipt, but it's breathtakingly disrespectful.

A hot tip for any baristas: Maybe, just maybe, don’t flagrantly insult the very people who keep your job and company alive.

One particular Starbucks employee must have missed that vital memo last week, when they decided to mock and belittle a customer who simply wanted to slurp on a grande iced coffee in the middle of the afternoon.

According to a university student from Pennsylvania, who asked to only be referred to as Sam, a Starbucks employee used their brief exchange at the cash register to mock his speech impediment.

“Okay, S-S-S-Sam,” he claims the barista replied after he made his order.

Moments later, the man noticed the name on his receipt was written ‘SSSAM’.

“It’s rare, as an adult, that that kind of disrespect happens,” the 28-year-old told The Philadelphia Inquirer newspaper.

“It happens, but it’s really rare to see it in print. It felt rude.”

After complaining to the company via email, Sam only received a generic automated reply, and a US$5 gift voucher to ease his concerns.

Noticing how unfair the situation was, Sam’s friend Tan Lekwijit took the matter to the coffee giant’s official Facebook page, and requested the incident be investigated not just for Sam, but for anyone with a speech impediment who may be discriminated against.

“I am writing this not because I want to get anybody into trouble, but because I want to raise awareness among the employees,” Tan wrote after explaining the situation.

“There are many people with speech disorders who are in a worse position than my friend’s and struggle with self-esteem and self-confidence. Getting this kind of treatment from people, especially service employees, only scars them—and I beg Starbucks employees to have this in mind.”

After Starbucks deleted the post from their page – yep, they deleted it – Tan posted it again as a personal status. Soon, it made its way into the media, prompting the organisation to take meaningful action, including a personal phone call from the company’s regional vice president to Sam.

“Admittedly, we didn’t do a good job of understanding the situation. It was not an appropriate response,” Starbucks spokesperson Reggie Borges told Fox News.

“We’re trying to figure out what took place and once we do, we’ll take the appropriate actions and make a decision on how to handle it in the coming days.”

While the situation is rather appalling, we can all agree: Everyone needs a friend like Tan Lekwijit.