How can get the divorce for my sister?

My sister lives in Sri Lanka. She was arranged to married to someone in Canada in 2006. After living with my sister one month, he came to Canada, he re united with his ex girl friend and refuse to sponsor my sister. We couldn`t do anything. We convince our sister to get married again and we asked him for the divorce but he is refusing to give her divorce. They haven`t live together since 2006 and we try to claim divorce in Sri Lanka but there are asking his letter but he is refusing to give any letter. Is there any way that my sister can get divorce?