THE WORST SERVICE 😫

I'm soooo frustrated and annoyed. THIS IS THE WORST COMPANY TO EVER BUY ENGINES FROM. About a month ago I bought a motor for my car from this company. Before my fiance paid he told the guy that it's not the proper motor the guy insisted it is and its going to work. I've paid cash for the motor and a delivery fee. They delivered the motor to my mechanic and my mechanic also said it's the wrong motor yet the sales person insisted that it was going to work. My mechanic then fitted the motor and the motor did not work so he had to do double the work to strip my car once again. It's been 3 weeks since we have returned to wrong motor and I haven't received a new one or my money back. If I knew this was the horrible service I would receive I would never have bought a motor from them. Now they are sitting with my money and I don't have a motor. This is ****ed up on sooooo many levels. And now I see that they are well know for the worst service. I will be taking this matter further even if I should make a case against them.