Do you always let the waitresses insult a guest? Granddaughter and a friend went to eat and her friend ordered a Dr. Pepper but when my granddaughter ordered a Dr. Pepper the waitress said she would bring her a Diet Dr. Pepper.

You put this out as an open question, but you need to direct your question to management at that restaurant. Apparently that waitress doesn't think young children shouldn't have sugar. That is none of their business. I would have complained to manager and not left a tip. A lot of times the franchise store number is on the receipt, call corporate to report the franchise. Don't call the store number. Everyone has their own opinion about this and I have mine. Outside of the sugar issue, when I order food at a restaurant, I to expect to get just what I ordered.

No I do not. When there are issues I ask for management or supervisor for that shift and make official complaint. Depending on complaint I contact regional office or post an update on the status of the place