Get a Replacement Mouse Cable

I recently got a Razer Mamba wireless used, but the cable was missing. I don't have a Micro USB cable thats small enough to not need the keying for the mouse. Is there any way for me to get a cable replacment? the mouse is pretty new, so it should still be under waranty, but I dont know if the waranty would be void because Im not the original owner? I was able to register teh product with razer, however, so should I just try to do a replacment through there? Thanks