Re: Clutch pedal not springing back to normal position!!
There may be air in the clutch line. Did they change the brake fluid, or have you let it get too low? I think on the 156 the clutch fluid uses the same reserve as the brakes. If not this then there may be a problem with the clutch master cylinder, or a leak here.
On the master cylinder there is a nipple, undo this and top up the brake reserve with new fluid. Get a friend to push the clutch pedal and fluid should shoot out the nipple, continue doing this for 10-15 presses and you should bleed the clutch line. Remember to keep an eye on the reserve and top it up while your mate is depressing the clutch.
If you think this is too much for you get a good garage to do it for you. Shouldn't cost too much, very easy job.
Hope you get this sorted.