Furious social media users have called out Starbucks on Twitter after their staff member cruelly advised a schoolgirl against buying food for a homeless man. Amy McIlroy, the 14-year-old girl who shared her ordeal online, explained how the barista asked her not to buy the sandwich, telling her to let "nature take its course".

McIlroy's honest but "pathetic" account of the situation left several online users shocked, who in turn left angry messages shaming @Starbucks UK for 'stigmatising' the homeless man.

"So f****** disgusted," the furious schoolgirl from Hamilton tweeted. "@StarbucksUK went into one of your Glasgow branches to get some food for a homeless boy who was physically shaking from the cold and was told off a worker that I'd be better 'saving my money and letting nature take its course".

"I'm at a loss for words," she wrote concluding her angry rant, which within hours have caught the eyes of several others on the micro-blogging site.

According to McIlroy, she was just trying to help 20-year-old Liam Anderson but, was "taken aback" by the "hatred and ignorance" shown by the Starbucks worker.

"I've never experienced that type of hatred or ignorance towards a stranger who hasn't done anything to merit such vile behaviour," she told Mail Online adding, "My friend was with me at the time and she was saying that the barista was not worth responding to but I told him that it was a disgusting thing to say and that I hoped he didn't speak for Glasgow."

While the teen's kindness has touched many a hearts on the internet, most importantly, it was the homeless man who was "overwhelmed" by the act.

"When the girl bought me a Starbucks, it was quite overwhelming, to be honest. I thought, 'Wow, people do care!" said Anderson, explaining how he was unfairly treated at the Starbucks outlet. "I was quite dirty and other customers get to go in no matter their circumstances. I was very shocked. It's unfair that I've been discriminated by the way I look. It's bang out."

Explaining his ordeal and how he became homeless, Anderson added, "My mum neglected me since I was about 14... Me and my sister went through care... I tried to leave care and now I'm waiting until social work gets me a house."

Amy's kind gesture and Anderson's candid account has since resonated with thousands of people online.

"That's disgusting. Why is it that so many human beings are incapable of showing even an ounce of empathy?" wrote one user.

A second one chimed in, "Thank god I stopped going to @StarbucksUK after they stopped someone buying food for a homeless person. This dehumanising of the poor is unacceptable."

"Honestly pathetic. Not everyone is privileged," said someone else.

"A fucking disgrace to think they have the right to say anything," wrote a critic.

As another added, "That's horrible but I'm not surprised. They shouldn't be allowed to trade due to blatant tax evasion in the first place."