Hi Pal
It's air.
best bet got to a dealer with a fixed price brake fluid change service and let it be their problem.
Be about £60 normally.
Alternatively remove the caliper from the carrier after tapping it a few times with a rubber mallet and then elevate it in the wheel well with the bleed nipple as high as you can get it and rebleed.
Don't forget to put a wooden block in the caliper if you are up/downing hence you pop the piston our
The VW machine pumps in at a higher pressure at than it sucks it out causing a positive pressure in the system, they also have a device that holds the brake pedal half way down, which avoids problems when pressure bleeding