WOW! That camera wasn't just used, it was abused.
i would be plenty upset if I got a camera in that condition.
I hope you get your money back or a brand new camera, whichever you prefer. There is no good excuse for something like that to have happened.
My husband who was a police officer did crime investigations. He would get his camera equipment in NYC, either on line or in person. There are many good camera shops that are honest and have great prices in Manhattan.
I wish I could remember the name of the shops he dealt with.