Ongoing car woes

[owlectomy]

As I was driving around Durham, just about to turn into the parking lot across from the great bookstore, dessert place, and sandwich place-- I stopped being able to steer. It just completely gave out. Fortunately I was close enough to the parking lot that I could just sort of edge it in there and parked it badly, diagonally, across three parking spaces; fortunately I had my phone charged and credited with money, so I called AAA and got it towed; fortunately it was just the serpentine belt, which shouldn't set me back too badly. But I took the car in two months ago; if the serpentine belt was worn, shouldn't they have caught that? Particularly since it could've been Real Bad if I'd been on the highway instead of downtown?