Dude I can sympathize with ya, I had a shop change rear wheel seals on my pickup.....left the oil outta the rear end and when I picked it up and drove away after about a mile or so the rear end began to roar !!!
The shop manager wanted to buy a rear end from a junkyard to replace the burned up one and bawked when I insisted they purchase an OEM pumpkin from the Ford house.
They finally made it good after I threatened to call my lawyer and Marvin Zindler from Eyewitness News ! This was a reputable national chain store that was supposed to know what they were doin.