Do shops still sabotage cars for profit?

i got a story for ya.i have an 2004 dodge ram i bought it with19k miles on it.i dont drive it very much.well i noticed a noise coming from the rearend so i call the dealership i bought it from and tell them they tell me to bring it in.when i get there i talk to service manager explain what noise its making.he has an attitude like im bothering him.so i answer the normal questions like milage,yr ex!!!! well then he says did u check the fluid in the rear.i tell him no i didnt cause i didnt think that was normal maintenance.then he says well do u check your oil.and i say yes then he says well the rearend is no different.so then i get mad and tell him.if i wanted to crawl under a vehicle and work on it everyday then i wouldnt of bought a new truck.long story short they fixed the rearend.then 3k miles later it went again.so dealer #2 fixed it right without attitude