brake discs bent

I bought brake discs from goldwagen parts about 3 months ago for my next upcoming service that was due 2 weeks ago. I then had them fitted and each time I hit the brakes my steering wheel shakes badly. I then took it to BOSCH SERVICE to find out what the problem was and they said I have warped brake discs and should return them.Who sells warped or bent brake discs. Love VW and now disappointed.