Bought a Corsair RGB ELITE from EVETECH

I bought the Corsair RGB ELITE mouse from evetech on the 27 March 2019.

Only got to use the mouse recently, I noticed sometimes the mouse wouldn't pick up on the Left and Right click. (The left clicks issue was more frequent than the right click).

Gave it to a friend that works by Evetech since I don't have transport to take the mouse myself. They said they'll test the mouse and didn't find anything wrong with it. Since the mouse was in a 100% working condition like they said, asked if I can maybe get credit and take a cheaper mouse. They said no I can't the mouse is too old to get credit.

I sent them a clean mouse with no oil marks on the mouse. That was a week ago, Today i received the mouse back from Evetech the mouse was in the condition i left it. Tested the mouse as soon as I received it today the issue is still there.