Help! I discovered seller/RE company Faking Radon test

[Jeff A.]

I have a contract to buy a house, and the seller agreed to complete a radon test,   It was noted in sellers disclosure there was a previous seller who walked due to radon.   So the test was agreed. I went by the house and noticed basement widows and doors open wide and testing equipment was in the basement, close to the equipment.    They admitted, but stated “someone” accidentally opened “upstairs” windows only.    What is th best course of action to take.  They are holding 3,000 Earnest money.  (Could I win, to get back if I walk).   

marietta, Georgia