Something weird happened at Jamba Juice

I ordered a smoothie there and was waiting for it to be finished.  Just then, this girl enters the place and starts talking with the guy in charge.  He clearly knows her from the way they talked.  As he was about to hand me the finished smoothie, the girl says like "can I have that..  please..  ?"  At first, he tries to brush her off and then she continues "please... ?" a couple of times.  He finally gives in and give my smoothie to her!  WTF?  I ask him for a refund but he refuses!  They just took my money without giving me anything back!  I really ought to report them to the headquarters but nobody's gonna believe me and I don't wish to get a lawyer involved all for losing the $4 I spent.

Any ideas?

lmao... Well to be truthful, if it happened to me I probably wouldn't have gotten physical, but I certainly wouldn't have let it go. Make a scene. Shout out "I JUST PAID YOU $4 AND YOU GIVE MY SMOOTHIE TO YOUR FRIEND THEN REFUSE TO GIVE ME A REFUND???"

Well if no one else was around, you could at least get in touch with the manager, tell the local papers, etc. Give them a horrible review on signonsandiego.com or the equivalent for your county.