Air Bag On-off Switch problems of the 2013 GMC Sierra 1500

Installing a child restraint system on the passenger side of truck. If the airbag went off it would injure or kill the child. The vehicle is equipped to hook up a car seat. There is no device to turn off the airbag when a child is in their seat. Nobody mentioned this when purchasing this vehicle that you should not install a car seat. Went to michigan state police car seat expert and the sarge tells me she has tried to get them to install a switch. I have the federal form saying I assume all liability . There either needs a switch or say you should not install a car seat. Calling gm I was told to put the child seat in the back. I have only one seat no back seat. I asked if I should install it in the bed of the truck. There response was put car seat in the back seat. I would if I had one!. I am afraid to carry my granddaughter in my vehicle. The sargent confirmed not to place car seat in the middle because if the drivers airbag went off it would kill her. The manual say don't put the car seat in the middle. If placed on the passenger seat it would hurt her and possibly break both legs. Gm refuses to install a switch even at my expense. They say it is a liability. It seems to me they are liable if they don't. Need some help so more kids don't get hurt.