The problem lies with the mechanical rights. Mechanical rights are payed to allow someone to create and distribute copies of the music. (For my younger readers: copying music used to be a mechanical process, hence the term ‘mechanical rights’.) This is a costly affair and therefore music distributors only cover these rights for the intended audience; you.
When you play this music in a shop, you make commercial use of the works and distribute them to a larger audience. The mechanical rights that were payed for this music do not cover such usage.You cannot strike your own deal with the rights handling organizations to buy off the mechanical rights. So put simply: until Spotify decide to cover mechanical rights for both personal and commercial use, there is no way you can legally play music from a Spotify system in your retail or gastronomy enterprise.
One solution is to buy your music from a specialized retail music supplier. They cover the mechanical rights for commercial use and you can therefore play their music legally. Note that this can be the exact same music. Lady Gaga via Spotify = illegal. Lady Gaga via an instore music supplier = legal.