Logitech has a really good RMA service. If you cant reach their customer service I would just go back to the place u got it from and see if you can replace the current one.
Just tell your problem to the guys working for Logitech tech support, they will most likely send you a replacement, I've had similar problems twice, they sent me two different mice as well.
yes i already did, they gave me some help with re installing software but the problem is still there now waiting what the next step is... because i didnt pay for this piece of shit :)