The wheel of my mouse is broken, so when I spin it down or up, it just jumps about randomly. This basically renders it useless, not to mention horrifically confusing whenever I use it without thinking.

This is particularly annoying as everything else on the mouse is working, including the mouse wheel button, so I don't feel justified buying a new one, especially as I just had to buy some new earphones cus my old pair broke (why is it always the left one that breaks first?), plus I've...