CBS Local — An Arizona Starbucks refused to serve a teenager on her birthday after the girl showed up at their drive-thru window on horseback.

Aspen Cline and a friend took their horses into the town of Anthem for a quick coffee run. “My friend and I were going to get frappuccinos for us and a cup of whipped cream for the horses,” Cline said, via WTKR. The teen had reportedly seen several YouTube videos online of Starbucks customers being served while on horseback and wanted to try it for her special day.

“We weren’t given a reason, just, ‘we can’t take your order,'” the teen added. “We were kind of disappointed we got thrown to the side from such a great company.”

A Starbucks spokesperson told local reporters that the coffee giant’s drive-thru is for cars only because of safety concerns for both riders and Starbucks employees. The spokesperson added that while Starbucks’ official policy bans horses, the barista was just startled and could have served Cline and her friend if they had been given advanced notice.