Great Way to Spend a Saturday

This morning a family from church called (at 8 am on a Saturday!) to ask if we'd babysit their toddler for a few hours. We adore their little boy, so of course we said yes. They asked what time worked best and we had nothing planned, so anytime would work. They said they'd call after his morning nap and let us know they were coming. So we waited. And waited. And waited. Finally at 1:15 I called and left a message on their voice mail, asking when he'd be coming. Two hours later they called and said, "Oh, he went to Grandma & Grandpa's instead."
Is it just me, or was that incredibly rude?