i am 2. if your mouse is faulty send it back. it has a 2 year warranty.
then again i did give fair warning to every 1 when i got mine last year. i said it had faults. i had to return mine because it would move the cursor when i used right click. the replacement is faultless though and i can say its the best mouse i have used in a very long time. tracking is spot on. the dpi can be set very close to my screen size or 16/9 very easily. the variable poll rate reduces prediction brilliantly and the acceleration can be truely turned off.
the rat 7 contagion in my opinion if you can get a working 1 is 1 of the best mice you can get.
if you want a very good mouse for not a lot of money then try the anker mouse i reviewed on here last week.
i would say go to the shop and test a few. then pick the 1 that has limited prediction and good acceleration management. try to find 1 that allows a true zero on acceleration or turn it off completely. some can some cant. but its a personal thing. so best test yourself to see what you like.