I had a somewhat similar problem. I took my car (maxima) to the car wash I always use, pull up to the vacuums afterwards and notice a slice in the sidwall of my tire. Its not all the way through and the tire's still holding air but its pretty deep. I assume it was the rail type thing that the driver's side tires go through.
I went over to one of the operators and told him, showed him my tire. And he said there was no way that could happen. I think he's just saying that to get out of buying me a tire. But before I can even say anything he says he'll show me.
He goes over to the entrance and hits the emergency shut-off button and walked me through the entire car wash showing me the rail the whole way. And he was right, there's a protective strip that covers the rail and it couldn't have cut my tire.
So basically, I'd just go talk to them about it. You might get lucky and have somebody like I did who will actually look into it.