Jewelry

Dear sir, 2017 my mother's cousin admitted in hospital for illness. After she recovered and discharged. She came with her husband asked financial help from my mother. For humanity That time my mother gave 12 saverign gold jewellery instead of Money. Jewellery pledged name of my mother's cousin. Few month later my mother's cousin got heart attack and passed away. Jewelly till in bank. My mother requested to her husband to return the jewellery but he telling not ready to return. My mother ready to give money to recover the jewellery from Bank and return back. He not ready. And ready to give 5 sovereign only. We have bills for that jewellery. Name of my mother with weight. How can handle this situation. Really he giving stress to my mother. Please help me...