Rey64 textbooks, especially the jacaranda one, should have examples of contemporary case studies. to be honest, you can sort of use any business that is operating at this moment in time. try using one that has been open for 5 or more years, as they are more likely to go through common stages a business would endure.
i use apple for all my case study references, but my teacher would always suggest to steer clear from fast food brands and controversial companies. you could literally use the local fish and chip store if you have one near by, and just make something up. (“the fishy fish and chippery (it’s made up if you couldn’t tell due to the lack of creativeness) should impose a participative management style to keep employees engaged, leading to increased staff morale and reduce rates of absenteeism”) you get the point (i hope).