Vibration after clutch replaced

Hi,
I took the plunge and had the dual mass and clutch replaced a week ago but now get a vibration when pulling away in first gear.
The clutch noise has all gone and gear changing when moving is OK.
I took it back and the garage said it was normal and I should give it more revs!
Normallly the garage give good service so left it a week and its still the same, I had assumed it was me as the release now happens when the pedal is close to the floor rather than higher up.
The garage did say they had problems in getting the gearbox out as was wondering if they had damaged the engine mount(s) as it seem to move a lot!?
Any ideas as what has caused the problem as the garage will no longer exist after this week! I have had the HDI110 57 plate since it was 6 months old and I could always let the clutch out slowly from standstill without a problem.
Thanks