Rear Window Defogger problems of the 2005 Volkswagen Jetta

The fuse for the rear window defroster melted into the fuse box. I called vw and they informed me that when they manufactured the vehicle they placed a 25 amp fuse in the fuse box and it should be changed to a 30 amp. They informed me that I can do this myself since there was a technical service bulletin placed on this. I told them there was no way that I can get the fuse out since it is melted into the fuse box, and they informed me that I would have to pay to have the fuse box replaced. I do not understand how I am responsible for something that I never did. I cannot use my rear window defroster, heated seats and my heated windshield washers don't even work. I have went the rounds with Volkswagen and they stick to telling me that I am responsible for the costs in replacing the fuse box. Its like they are telling me that I built the car and I placed the wrong fuse. If I did build the car and place the wrong fuse in the car I would pay for the damages associated with this, but I did not build it vw built it and I feel they need to take responsibility for placing the wrong fuse in the fuse box.