Hi,
It's a little unusual to read a positive report and an hour and a half later it seems no good. A new stylus usually requires at least 5 hrs or so playing time to break-in. This is a mechanical thing and it could take 7 or 8 full albums.
Did you ever check the set-up parameters on your cart which came with the table? Alignment and VTF (at the very least) should be checked. You also might need a small height adjustment on your arm (up?). If you're going to have a successful long term experience with records, this sort of thing is a requirement. Are your records clean? Another essential ingredient.
Unfortunately, unless the stylus is defective, you probably won't be able to return it without a dispute, and rightfully so. I think it might be okay and you haven't given it a chance? If you look at it with a magnifying glass, does it look okay? Maybe we can help you figure it out.
neo