Is it a 'clunk' or a 'ting' noise.
Quite often its the dual mass flywheel that 'tings', it should have been replaced with the clutch really as for the gearbox bearings, the gearbox oil should be checked/replaced on some services to prevent excess wear/damage to them.
If the parts used are non manufacturer parts ie 'pattern' or 'factor' parts these can cause all sorts of issues.
Personally I will never use anything other than genuine parts on any of my vehicles, yes sometimes they are more expensive but they last much longer and fit and work first time.
It may have lost gearbox oil when the drive shafts were removed to do the clutch, so the garage might have not topped it up or used a sub standard/wrong grade oil, which caused the bearings to wear excessively.

I would guess at they didn't top the oil up and used a motor factor 'cheap' quality parts.

Hi thanks for your reply this has had 2 genuine LUK clutches and still have the same problem it is a clunk fiat are saying this is normal why when it was running ok

The only thing I can think of is that the new clutch is different/modified in some way to cause this.