i am in middle of the process to get polish citizenship through my grandfather and i got a negative answer through a attorney in Poland would you be able to help me in this case?
Nobody can: you do not qualify for Polish citizenship.
he acquired foreign citizenship 1948-1950
Doing that lost him his Polish citizenship. Have a look at the Act on Polish citizenship of 8 January 1951:
Polish Citizens Art. 1. A Polish citizen cannot be a citizen of another state at the same time.
Loss of Polish Citizenship
1. A Polish citizen is permitted to obtain foreign citizenship only after receiving the consent of Polish authorities.
5. Obtaining foreign citizenship (art 1-4) leads to the loss of Polish citizenship.
Given that your grandfather almost certainly did not get permission to take Israeli citizenship, he lost his Polish citizenship when he did that.
Sorry but you'd be wasting money on a lawyer in this case.