Bushes are not supplied split. It sounds like they fitted them the wrong way round. Inners are a different size to outers, if they got them wrong they would have had to split the small ones to get them on and the large ones would be loose hence the clunk.
'08 Chrysler 300CRD (MB OM 642 engine)
'95 E220 estate
'89 230TE (R.I.P.)