Broker is not refunding my Initial Booking amount of 3.75 lacs

I had been approached by a company namely AVHM Global Pvt. Ltd. 1st floor,H-190, Sector 69, Noida. They said to me that they are a builder firm and they are developing a plotted residential project namely Green City, Near Jewar, Dist - Aligarh. I booked a 200 yards plot and paid Rs. 2,50,000 as 10 percent of booking amount. I again paid them Rs. 1,10,000. Later on, I came to know that the so called AVGM Global is not the actual owner of the land which they are selling rather they are just working as an agent. I have no idea about the actual owner of the said land which is of a total area of some 8 acres. Even, the AVHM Global Pvt. Ltd. is not registered with RERA nor the Project Green City. AS per my understanding, no agent or project which is of an area of more than 500 yards can be sold or promoted without registering it with RERA. Now, the AVHM Global is not refunding my paid amount. They are saying that they will forfeit all the paid amount. They are also threatening me. Please help suggest me what to do now.