Starbucks Partners Spotify Premium on multiple devices?

[user-removed]

I'm currently using free spotify premium offered to starbucks employees on my iphone, and just now downloaded spotify for my laptop, but it's not Premium. I tried entering my Starbucks partner numbers to get Premium on my laptop, but it says that my numbers are already being used (by me on my iPhone is what they mean I'm guessing?) It's the same account tho, I even checked on my phone (not that I've ever made multiple spotify accounts, at least not that I remember) and all my playlists i have on my phone are on my spotify on my laptop. So it's the same account, just no premium. Any reason for this?