Re:any vw passat owners with push button handbrakes - experiencing a problem
You should have got a decent warranty with the car mate it's only a 55 plate so in my rekoning you should have got 12 months warranty with it.
Some good advice regarding taking it to a normal garage instead of the main dealer, if the normal garage is ok and VAT registered I'd get the work done there if I were you, looking for a ABS pump is not hard, look for a local company who bring the cars in off the motorway after they've been involed in a smash, you'll get some good parts off the write offs.
I've got a Passat with the same parking button as you but upto now I've had no trouble with mine, if I do get any trouble with it I take it back to the dealer where I got it from.
I'd look at your purchase form mate and see if you've got a warranty with it.