When my kids were around 9 and 11 years old, they still ordered from the kids menu, but at Olive Garden they used to bring them full-sized drinks instead of the kiddie cups. We never asked for the bigger drink and assumed the waitperson was being nice and thought he/she would save a couple of trips making refills on the smaller cups. But when the bill came, we'd get charged for full-sized drinks for them. The first time it happened I brought it to the attention of our server thinking it was an honest mistake. It wasn't.
She said, " Well, they had full-sized drink." I told her #1, we never asked for full-sized drinks, and #2, the drink was included with the meal with the design cup for the kids to keep. (Frankly, the cup and sturdy plastic lid probably costs more than the extra ounces of soda). Since the kids soda & cup were included in the price of the meal, we were essentially being charged for two drinks per kids meal. She took the drinks off of the ticket, but the same thing happened the next time we went back. And the server again tried to justify the higher price. The third time I told the waiter to just bring the kids cups if there was a charge for the larger drink.
I told a friend of mine about it and she said the same thing happended to her family, so watch your receipts from Olive Garden.
Another additional charge that Olive Garden is famous for is asking if you want dipping sauce with your breadsticks. The server doesn't tell you that there's an extra charge (nearly $4) for the sauce. IMO, if a server asks if you'd like something that they know costs extra, they need to be upfront and tell you about the charge.