This is happened to me more times than I can count. Adults say this to me and laugh, which always surprises me. That's the type of immature reaction I would expect from a young child. I started to go by a different name, a shortened version of my own, which is easier to say. It begins with an "S" sound, so when I say, "My name is xxx, how can I help you?" any stutter is hidden by the connection of "is" + my name.