Hi Jelly
Thanks for being the Virgin post in this section!
If your guitars is one of the new Band Hero specific guitars (easily identified by the red cover and the 'dimpled' rubber strum bar) then a new guitar may be on the cards, if however yours is one of the GHWT guitars (identified by the yellow cover and smooth plastic strum bar) then you will be in luck and can try our strummer repair kits which will solve all your strumming woes!
Here is the link to the repair kit mentioned:
Guitar Hero Strummer Repair KitAlthough it states this is a Guitar Hero Repair Kit, it will work with certain Band Hero Guitars (as long as they are the yellow ones with the smooth strummer) and the explanation for why this is the case is that when Band Hero was launched it was still being shipped with GHWT guitars for a while.
Thanks for your post!