Two registry of same land with different plot number

Hello Sir, My family bought a residential plot in the PUDA approved colony last year from a private builder. All the fees, measurement fee has been paid to that builder.Goverment registration is also paid to the municipal cooperation .After that the builder gave us the demarcation of our land. We have plan to build a house on it after few years .We also took loan for this land from a bank.The legal representative of the bank has verified that land and passed our loan. Now I am coming on the issue that I am facing. Two weeks ago I visited that land and saw, Some one is building on it. I reported that issue with the builder and he stopped the construction there for two days,but after that they agian started the construction, So we met with the builder with the other party who is constructing on our land .It seems that builder has issued him the NDC for the same land with different plot no and mentioned him that it is a corner plot. What are the legal ways to deal with this situation ?