Hey, my girlfriend recently got a new clutch done on her 2012 polo, and it has started making a clunking/ grinding noise when the clutch pedal is not engaged and the noise stops when the clutch pedal is engaged, i was thinking that it could be a input bearing in the gearbox(more then likely wrong) or the mechanic installed the clutch disc or flywheel incorrectly and didn't use an adjustment tool. Just posting if anyone has any ideas, thanks

It definitely sounds like a release bearing which may be slightly contacting the clutch cover plate diaghragm.
This can be caused by incorrect clearance (if it is manually adjustable) - this will need to be checked that the marginal gap is there.

Sometimes it can be aggravated by the driver resting their foot on the clutch pedal and this takes up the clearance which means the bearing is spinning with the engine rotation which if anything more than idle can wear the bearing and create the noise.
Once you depress the pedal then the bearing is under load and the noise disappears.

Alternatively it could be a cheap clutch kit which includes the bearing.