I dropped my car off on a Thursday to get serviced...

I dropped my car off on a Thursday to get serviced over the weekend, and was assured that my keys would be waiting at the Sales Desk for my on Sunday, as long as I showed up before 6 pm. When I showed up at 530 pm, the guys at the Sales Desk had no idea about my car, and said there was nothing they could do. They didn't offer to help me at all, just told me to get an Uber and come back the next day. How is that in any way acceptable customer service?