Refund of money against non allotment of plot by BPTP

I was allotted a plot in one of BPTP's project in faridabad. I paid Rs.10.7 lakhs. Because I shifted from one city to another I sent a change of address note to BPTP. BPTP acknowledged this change However requests from BPTP for subsequent instalments were sent to the old address.i obviously never read them. On a query on the progress of my plot I was informed that BPTP has alotted the plot to someone else. Upon my request for refund, there is no response rom BPTP Please advise next course of action