Even if VWoA would be willing to do something, there is still the stealership, which could stand in your way.
Try putting yourself in the VWoA shoes: you have two statements, one from (very often clueless, but convinced) customer and one from the dealership, which employs a bunch of "trained professionals", whatever it means :) Which one would you believe more? :)
Of course, VWoA could say "do whatever it takes to keep the customer happy, we pay". But it is way different from saying "ok to change the faulty cylinder under the warranty" and requires _much_ more commitment from the VWoA side.
Of course, morons at the stealership is the problem of VWoA, not yours. But I would still try to speak to other dealerships in your area. In case of success you could provide a feedback to VWoA and know the proper place for the next time you need one.