@bhbh I just looked on the Hyundai technical information website. Unfortunately, I can't post the maintenance schedule.
For normal service:
Inspect the timing belt at 60K/48 months.
Replace the timing belt at 90K/72 months.
Unless they physically inspected the timing belt (which I SERIOUSLY doubt) and can prove it's bad, I would be tempted to hold out until 72 months.
Here's a question.
When you go the Hyundai dealer for a scheduled service, do you receive a printed sheet which the mechanic has to check off? If you do, perhaps there is a box that says "remove valve cover and inspect timing belt). Unless that is the case, I suspect the valve cover has never been removed.
IMO I believe the dealership's trying to drum up business.