Someone else using my LPG connection after I lost booking card

I had taken a connection of LPG from my dist. agency.i was getting service regularly.manwhile my gass booking card was lost by vendor.in spite of that agency guided me asking that do the zerox of ur original gas connection card.on the reverse page of original stamp will be stamped.it will be work as booking card.after a few months letter new agency setup in my locality.all the consumerships were transferred to local agency.i approached my local agency to get the LPG service.but,his reply was shocking.he said that another is getting benefits on only booking card basis which was lost by my vendor.i showed my original connection paper.also gave application enclosed with all originals.but no response.i paid connection fee but fake consumer is getting benefit only affidavit ground of ' i am genuine consumer,if anyone claim, i will lose my consumership.

please,suggest me the action we should take.