THIS IS THE SOLUTION.
I also struggled with your issue and having read all the comments I emailed razer support for an answer.
Their response was this...
"In regards of the matter, your mouse may need to have the surface calibration reset. To reset this please log into the Synapse 2.0 software and press and hold the Left, Right and Middle mouse buttons (M1, scroll wheel, M2) for 5 seconds while the mouse is plugged in. After resetting your mouse you should readjust the surface calibration within Synapse."
I didn't even need to do this. I had unplugged my razer deathadder 2013 and was using another mouse. Having read this email I plugged my razer back in and the problem was sorted. I believe the mouse will auto-surface calibrate upon being plugged in and powered up so just make sure the mouse is on the surface you plan to use and the issue should be cleared up. I sincerely doubt replacement will be required if you do as I did and follow the razer support instructions I have posted above.
Hope this helps anyone who is having this issue!