By the time I took a sip, I was already too far to go back to the store. How do I complain? Is there an email? Or do I call the store? I looked to see if there was something under my rewards account but I don't see anything. I even looked on starbucks website for a contact info.

This has happened in the past and I usually don't do anything because I can't figure out who to contact when this happens. Haha

I really should say something when it happens or take a sip before I leave the store.