Vandalism on a car I bought on Auction

Have been dealing with this company for 13yrs seems things are changing rapidly,we now buy cars online and thats enough risk for any body buying online,you are liable to incure more cost on the damages,but for you to buy a little accident and then your car comes and you find out your catalyst has been removed from the car ! took the car to an exhaust expert ,to my surprise I was told the catalyst is out ! that's i ridiculous and sad,now the car is not functioning the way it should causing more expenses on the car. Am so disappointed!