A took life insurance policy of 10K and another of 20K. If requirements are fulfilled, can they claim both policies in case of contingent happened?

Each insurances has their conditions policies. To claim is easy, just do it. But the resulted that you will get..in it.

Well unfortunatly, we dreams on receive full payment amount from the insurers ..etc. It will be depend of the contract, never will get the premium amount paid. not 100%

Yes A can claim both the policies since they are two policies and two separate premium amount paid (assuming that the claim conditions are met)

The insured cannot recover more than the actual loss and cannot claim the whole amount from both the insurers.