Most likely they just used cheap of cheap crap to keep there costs down. You'll need a press to pop the bearing out the hub just saying incase ones you've done in the past was different set up like a rear wheel bearing on a ford ka is totally difference.
Just use old bolts unless you round them off etc 
A press to pop the bearing out of the hub? Haven't done this before! Any advice?
Unless you know of other ways? If it's the front you remove the hub then set it up on a press bench then press the bearing out and press the new one back in using the press again. Rear wheel bearings can be different most I've do e are bolt on one but I've never payed any at tension to what's on the rear of my golf so no idea.
EDIT- I didn't read your reply properly ha it's fairly simple but can be a little tricky to set the hub up on the bench so it's level etc I use blocks of metal and old sockets for this. Remove the part where the wheel bolts screw into then remove clips on bearing then press it out, press new one in then make sure when you press the wheel bolt thing back in to the new bearing make sure you place something underneath the bearing so you don't fk the bearing. I use the old bearing to press the new one in to as it's the perfect size so you'll not damage the seals etc.
I'm crap at trying to explain things
