Suggestions regarding Gold ornaments given they're not returning.

Hi, We had provided gold ornaments to one of our friend in the year 2013, while providing the ornaments we didn't not go into writing in agreement because they were know to us and they had told we would return with in half year they have not even paid any interest till now.When ever we try to ask they used to tell we will provide in one or two months but now when we asked them when will you return they told won't return you because you there is no proof that you had given me,as a proof we have recording and video recordings where they are talk and arguing that they won't return back.please do suggest me what can we do whether we need to raise a complaint or send a notice. Thanking you