transit connect gearbox problem

[djoauto]

hi. new the site so hope i am asking in the correct area.
can anyone help me.
the other day i was driving my 2003 connect, i pressed the clutch in and released it to coast down a hill. when i put the car back into gear i heard a really loud clunk/bang, and it felt like the gearbox was trying to jump out of the van. i pulled over onto the hard shoulder coasting and wiggled the gear stick about and managed to get it into 5th, so i carried on slowly to get off the motorway.
i pulled up and it all seemed ok after wiggling gear stick about, but i had no 2nd gear at all. drove it gently for a few days while i sorted a used gearbox out, as i drove it it got worse in first gear and reverse it physically jumped and gave a very loud clunk, so i parked it up.
brought a used gearbox and took it to local garage for gearbox swap.
they swapped the gearbox for me but i still have the same problem very very loud clunk/jolt. i do have second gear back though. the van is undrivable.
the garage said its probably clutch (why they didnt check it when they were swapping boxes i dont know i did ask them to) or drive shafts.
has anyone had this problem or know how to fix it.

[karl]

change were you take ya van to for repair they clearly dont have a clue