This liberty is claim, is a ****

My father passed away 11 Dec 2017, I have been claiming for my father's policy claim, been sending documents since 2018, till today they lost some of the documents, and keep on making the same claims of receiving and not receiving some, yet everytime I submit a document they keep asking for it,

Im tired of them, and I have proof of each email, that sent a document, just need a good lawyer,