Nehawu Sacco not paying back my savings

I used to save money with Nehawu Sacco. One could save and withdraw the savings as time goes by but in 2018 when I wanted to withdraw my savings, they told me to leave it and let the money gain interest because I had told them that I wanted to resign at work. After I had resigned, I went back to them to withdraw my savings, that's when they told me that they couldn't give me money because they lost the money. Till this day, they haven't given me my money.