I have a question for you???

Okay we went to a place called Jamba Juice. My question is? Why do they have on their price list (example) Mega Mango- $7.75? Then they charged me $1.16 gratuity, which now is $8.91? Why would they charge me gratuity for standing in a line and waiting to be served? Why don't we have to pay at McDonald's gratuity? Or even Burger King? Now if they have their prices at $8.91, I would have walked away. Remember this is a fast drink place and why is it soooooooo much? I can tell you this I will not be back into that place ever again. I am calling the manager today to ask him these same questions. I know he will blow me off and think no more about this. But I know I will be passing this on to others.
The drink was okay, not worth $8.91.