Intestacy rules not followed

Hi I wonder if any one can help please.
My grandmother died in May and despite her telling me that my Uncle had her Will - it has now transpired that she has died intestate leaving 7 children. She often told me how much money she had and since her death my uncle divided her estate as he pleases. He has left 2 brothers out and not shared the remainder equally. I believe her estate to be approx £50k but I have no proof only my grandmothers word. He has offered no explanation on how her estate was divided - he hasnt applied for probate or letters of administration and simply gave 4 envelopes of unequal cash to his 4 brothers and sisters totalling £20k.
When finally asked for an explanation he said he was highly offended and refused to meet up to discuss further. We politely wrote to him asking for an explanation and he wrote back admitting that he had not followed the rules of intestacy and asked all family members to return the cash they had received in order for him to now divide equally. He knows that this is not possible in my mums case as she bought a small car with her share. He has also offered no explanation on the value of her estate or offered to provide proof.
My mum and uncle have sought legal advice but have been told by the firm that due to the small estate it would not be beneficial to the family to proceed down the legal route as the costs would outweigh any benefits.
Does anybody have any suggestions on how we can get some closure on this, a i feel he has manipulated the situation to his advantage and potentially stole £25-£30kk from my Grandmothers estate. Please help