Wow, good mouse but bad wheel. You can ask where you bought whether it can be replaced due to bad quality on the wheel, some shops might not accept this as "malfunction" product, cause it's still functioning.

WARNING, GOES BEYOND THIS POINT MIGHT VOID YOUR WARRANTY.

If the shop don't allow, check whether the RMA sticker is right on the screw, if not, take it off and do some mod on the wheel to make it smoother, like bent the steel wire a tiny bit lower, it should lower the clicking noise when you scroll but lower too much and you'll have a "free run" wheel.
This is how I mod my MX518 right after it pass the warranty period.

Probably a manufacturer defect, send for RMA and see if they accept such defect, every logitech mouse that I used does not have this issue, very solid even under stress and long term usage.