72yr old father

My father was referred to old mutual after working 33 years. He was told by the person from old mutual that was "assisting" he could invest his money for 15 years and he would have access to it after. He was not told it was actually an annuity and that he wouldn't be able to ever have access to the money he had worked hard for. All so the person could get a big commission. Nothing else was ever explained besides that it was an investment and he would get paid every month for 15 years my father took the majority of his lump-sum and transferred it to old mutual. My father is 72 years old, he had to borrow money to pay for school fees throughout the years because the amount he gets every month isn't enough he has had stop construction on his home because he doesn't have enough money. Old mutual claims he knew what he was signing which couldn't be further from the truth. None of the jargon was explained to him he was just told to sign the "investment contract" now he is told he can't access his money nor will his family inherent any of because it now belongs to old mutual. They now keep denying the fact that nothing was explained to him. Shame on old mutual for denying an old man what is rightfully his.