Money in exchange for talaaq

Asalam alaikum. I have been engaged for a year , and two months before my marriage problems started to exceed between me and my husband. The way he was treating me and my family was brutal. I want talaaq but he refuses to give it without exchange of amounts of money. He had no expenses for me but the engagement ceremony. I gave all the gifts and gold back. After the whole argument and separation he soon wants to marry someone else, which now explains why he treated me and my family the way he did. He tells my father he can have four wives and it’s sunnah. Made many lies saying I had an affair with my cousin. Since he’s my second cousin, it’s been said that he asked how talaaq is taken. I feel like he took talaaq but just wants money. Without $30,000 in his hands , he won’t give me talaaq. What do I do ?