You've probably been quoted for the 4-year 40,000 mile service - ie based on mileage, not time. They probably change more than the 20,000 miles or 2 year service.
I understood that since 2013, Santa Fe servicing has been every 20,000 miles or 2 years, whichever occurs first - but with an optional, ie non-mandatory, oil change at 10,000 miles or 1 year.