Change your business model
The costs associated with a physical location in retail doesn't allow for competitive compensation packages for many hourly employees. This fact coupled with the current inability of millennials to work from home has caused stagnation in this industry. However, ManPower Research Group and its report, Millennial Careers: 2020 Vision
will tell you that 79% of millennials prioritize a healthy work-life balance over any other job aspect. Capitalize on that by giving them work to take home occasionally.
In the age of E-commerce, it may be more fiscally responsible to work from home at times. If that doesn't work, bring the home to them. Provide your millennials with a comfortable workspace. Referral bonuses for new hires can represent a quid pro quo, if you will. Your employees will enjoy the idea of getting a bonus to work with their friend, and you earn reputable (hopefully) staff. Hopefully this inspires and gives them freedom to change the brick and mortar business model.