Amazon has illegally deducted taken amount from my account of 850 USD in other payments and i am unable to open a case
please help and guide how to create a case and recover my money.
You need to find out what policy you violated and fix that. Be aware, in terms of service, Amazon does state that if you violate certain policies your money will not be returned to you until 90 days after violation. I believe there are a few cases where they may not release your money at all. You did agree to this when you agreed to Terms Of Service. It is not "stealing" or "illegal" if you agreed to abide by their policies when you agreed to Terns Of Service. Unfortunately, no one here can help you without knowing what your violation was. You may want to post that so we can help.
No, what would be illegal would be if they gave you the money from your unauthorized and undocumented sales.
If you really find this policy objectionable, then you should not have agreed to those terms when you signed up, which specify that Amazon will not release funds from sale of counterfeit products (and it's up to YOU to prove the items are legit; the burden of proof is not on Amazon to prove that they are not).