Honestly it all boils down on what you're comfortable with. For Claw/Ftip the Viper V3 Pro. For Relaxed Claw/Palm the GPX 2. They're both premium and have good warranty.
Not sure how long you been using it but if you still getting cramps after a week and half or 2 weeks of use then its just not it and its best to return it if possible.
can you check if your mouse scroll moves left and right side when you push it? like it wobbles/adjust but not to the point that it makes wobbling sound when you shake it. pacheck naman boss.