2005 b6 2.0tdi clutch problems

Hello all....

Looking for some help, here is the problem. any advice would be appreciated...TIA

BACKGROUND

bought car 2 months ago from trader, problem selecting 1st and 2nd gear within first week, trader arranged for garage he uses to resolve, had
clutch, master and slave cylinder.

SYMPTOMS....since above work carried out.

Initially on occasion the clutch pedal would be slow to return to its starting position after changing gear, this has gradually become more frequent.
Today after changing gear the clutch pedal stayed on the floor, but i was still able to select gears and drive.
I was able to lift the pedal by hooking my foot underneath it.
The clutch then operated normally for a few miles, then the same happened again but this time the car wouldnt drive whilst in gear, again i managed to
return pedal to normal position by hooking my foot underneath it...I proceeded to drive home and the clutch operated normally for the journey home of about 3 miles.

since the clutch, master and slave cylinder were changed I have covered about 10k, all gear changes are smooth and free of problems, I know when carrying out the work the garage had a problem with bleeding the clutch system.

Could it be that the clutch just needs bleeding or does it appear that there is a more major problem.

TIA for any advice