Payless Car Rental not a waiver but an acceptance Internet

All was normal at the airport rental office at the Las Vegas airport until I told the clerk that I had my own Insurance (He asked what Company).  He then completed the check-out tellingme that the box that says collision damage waiver was just that a waiver it turns out this was an acceptance for a charge of $22.95 a day. That was more than the car rental charge ($19.95 a day).  The facility Manager (Kevin) was absolutely no help. I will never rent from payless again & I'm posting to every web site I can find.