Ampco System Parking

I decided to park here during the Glee concert in San Jose. The sign outside said $ 7.00 to park for Special Events. It did not say what event and it did not say that it was going to be a different charge for a different event. I thought well a HP Pavillion show is an event so I parked.
After the show, we headed back only to be charged $ 20. It was not exactly what they had advertised outside the parking lot. I questioned the staff about this and she said that it was only for any events until 6pm which was not indicated on their sign outside.
I would think twice and question any parking lots in the vicinity in future events in that area. Deceiving and false advertisement is the take home message here.
Thank you.