I know this, you are FAR more likely to get a replacement ball BEFORE you try any repairs than you are if you do some work to it and then try to get it replaced. If you bought it through a local shop, they should be the ones to help you with the problem. If you bought it from an online outlet, then the person you bought it from should be the one to handle the situation.
The balls, in general, have a warranty on them against defects in workmanship, but most also state that any warranty is voided if you install grips, or if you drill ANY hole within 1/2 inch (or maybe 1 inch) of the pin. Many times your shop can get the distributor to go ahead and warrantee the ball anyway.
Many times, a major manufacturer will balk at dealing with an individual over a single ball.
Good luck.