If you read this on the Vespa forum---they want to change spark plug (surely not needed) replace drive belt ( again not needed)---expensive oil, etc, etc---I would change oil and filter, look for junk falling off, test ride.
After over 75 new bikes since 1955---I seldom return bike to dealer for service----many cases, Germany/US they just screw things up-----Japan/Korea work done right by somebody who knows what they are doing