Bad attitude and cheating

We had a rental from them thru our insurance,the day we went pick up the car we were in the shop sorting out the paper work when they send the security guard to check the car we were not told to go with him i went out later and he was done with the checks when we returned the car we were told that there is scratch at the left bottom of the bumper the black lady that went to do the check checked the boot first then walked strait to front left and said there is a scratch there without even checking the rest of the car and may i ad the scratch can not be seen without bending down and looking under the car so it is my opinion that they knew about it and that they are ******** people and there insurance (PS we hardly ever used the car my wife just went to the shop now and then and there is no place she could have scratched it like that without knowing) so i would like them to bring me video evidence if they have to prove that they did check there