One California Starbucks barista got a major surprise on March 21 when a customer returned to apologize for her behavior from the day before.

Andrew Richardson, 20, was floored when he received a handwritten card and $50 bill from his customer named Debbie, whom he admits he didn’t even think was that rude.

“On the 20th, this woman, Debbie, came through the drive through while I was working. She was extremely pleasant, and we had some friendly conversation while her drinks were being made,” Richardson, of Bishop, California, told ABC News. “She had multiple drinks, and we didn't have drink carriers. I informed her and she was a touch frustrated like anyone would be.”

Starbucks barista Andrew Richardson was shocked when a customer returned with a handwritten card and $50 bill to apologize for her behavior.  (Courtesy of Andrew Richardson) Starbucks barista Andrew Richardson was shocked when a customer returned with a handwritten card and $50 bill to apologize for her behavior.

In addition to being out of drink carriers, he also couldn’t take her trash she was hoping to throw away.

“I cannot do this because it would be a California health code violation,” he explained. “She then became a bit more frustrated, but nothing that I would perceive as rudeness. At worst, she was playfully sassy. I really didn't think too much of it.”

Richardson carried on with his day and didn’t give it a second thought.

“It was not a big deal at all in my eyes,” he said. “Being in customer service you can experience a lot of negativity and frustration. I try and counter it with positivity and patience. This was an extremely mild interaction compared to other incidents.”

But Debbie apparently felt otherwise.

“The next day, she came back. I happened to walk by the window when she was there,” Richardson recalled. “She asked me if I was working the window yesterday. I said ‘yes.’ She then became extremely apologetic. She felt genuinely terrible about our interaction the day before. I was so heart warmed to even get a verbal apology. It doesn't happen much.”

The two chatted for a few minutes and Richardson said her in-person “genuine apology” alone was enough to lift his spirits, without even knowing what was going to happen next.

“She then handed me the card, [and] I was even more grateful and uplifted,” he said. “I thanked her for another minute and she left.”

He hadn’t yet opened the card before Debbie drove away.

“I returned to it later, opened it, and I was completely shocked,” he said of discovering the money. “Without the money, this was one of the most beautiful and heartfelt things I have ever read. It absolutely made my day when I read it. The money was unnecessary. The card alone was the best part. I would have turned the money down had I opened it when she was there. It's hard to take things like that.”

Starbucks barista Andrew Richardson was shocked when a customer returned with a handwritten card and $50 bill to apologize for her behavior.  (Courtesy of Andrew Richardson) Starbucks barista Andrew Richardson was shocked when a customer returned with a handwritten card and $50 bill to apologize for her behavior.

Richardson’s supervisor told him he could keep the money.

“She handed it to him in a personal card so of course he was able to keep it,” one of the location’s supervisors, Angie Harris, told ABC News.

“I think it was great. It’s always good to see those customer connections,” she added. “We’re really proud of him.”

“Nothing like this has ever happened, it's unprecedented,” said the humbled barista. “This was easily one of the kindest things I've ever received. I'm very happy to know that there are still good, caring people in this world. I'm still smiling about it.”