About the quality
Hi, I have bought this mouse in September and used for just one month.Unfortunately, the middle wheel goes broken....Is there any quality guarantee for this product?
You should contact HP and see if they'd be willing to swap out the unit for you if Best Buy isn't willing to do that for you. I believe most accessories only have a 30-day warranty, so you might be out of luck, sorry. If anything, all the better for Best Buy to encourage you to pay for their extended support/warranty option.