SAPO doesnt pay out pension money !!!

My dad has been working for the post office for over 25 years. And when he fell sick, he just couldn't do it anymore. He retired at 60, and took 1/3 of his pension money. A year and few months later he passed on, and my siblings and I never got any of his money. We were still in varsity, and struggled to make ends meet. But the South African Post Office denied us what was rightfully ours. We wrote to them, and their reply was that this thing could take years. 6 years later, we still havent heard from them or received anything. Is this how these things work, people are advised to take only 1/3 of their money and when they pass on it disappears? I wana know where the money disappeared to .