For your seat I suggest taking it to an upholstery shop. My 2009 CVO Springer stitching was coming apart and the moco would not repair under warranty. The upholstery guy took the whole seat apart and restitched everything for about $100. Not a problem since.
Why would they not repair or replace it under warranty? The bike has a two year warranty, basically "bumper to bumper", and the seat is most definitely covered under the defective crap clause. Was this your dealer blowing you off, or did you actually contact Harley-Davidson corporate customer service? They tried this same BS with the Road Glide guys not too long ago, and eventually they changed the seat to eliminate the highly stressed area where the stitching kept tearing out.
People who persisted got new seats.
Jerry