Remedy if a plot is registered on the name of two allottees

I have purchased property from one of the vendor in year 2011 after 5 years i came to know that the purchased plot was allotted and registered by the Housing society to two members at 2003. The person who was allotted first A was keeping the plot and not sold to anyone. The one whom I purchased plot from the Y fellow was bought it from the another fellow X ,Who was the second allottee from the society. So please suggest me the procedure to resolve the issue. I tried with the Society chairmen and other folks but it was worthless as they are asking for lot of money to resolve it.Currently am having only the loan and papers of plot not the position. Current the plot is in with position of First register fellow A. Is it better to Approach the consumer court ? or any other correct procedure ?