First step would be to go back to the garage for them to confirm what the noise is and that is was (or wasn't) caused by them.
Diagnosing a noise on-line is very difficult.
It could be totally unrelated to what they did or it could be that they disturbed (or undid) something which is now causing the noise.
I recall once driving a 90 with a very disturbing rumbling coming from the back axle (very pronounced on over-run).
A quick inspection showed that the rear axle ball-joint hadn't been seated properly in the axle and although the nut & split-pin were fitted, the taper was moving about in the axle. Split-pin removed, taper seated properly, nut tightened & split-pin fitted and it was then silent.