My car is not working now!!!!

I took my car for a simple procedure which had nothing to do with my engen and the next day my car was ruined to the point where something was broken in the engen and the car can no longer be driven. I drove it there the previous day and it was driving fine and now I needed to get it towed to new mechanics to fix as I no longer trusted car service city with my car. To make it worse they had the audacity to tell me that if they open the engen to look what's wrong and I don't accept their quote they will not put the engen back together unless I accept the quote they give me. I am absolutely appalled and disgusted!!!!