135i Auto Axle bolts

[dsocold]

I had my differential replaced and 3 months/1k miles later i was gonna launch the car on the on ramp and kaboom axle disconnected from the diff. I go under to see the bolts completely backed out of the left rear axle and it disconnected itself and the other side axle most of the bolts were damn near half way unscrewed. I suspect the shop re used the bolts and maybe they did not put loctite on them either has anyone experienced something like this before?.
My car is fbo xhp stg 3 mhd e50 stg 2+.