Common Wall Dispute

I live a row house tenament. I built my 1st floor and 2nd floor terrace cabin 2 years back. I have a common wall between neighbour. Now this neighbour started his construction of building 1st floor and 2nd floor terrace cabin. As per Common Wall subject, I told him to pay half the amount of common wall to me. As per my contractor's estimate and my neighbors contractor's estimate, the total amount of common wall to be paid by my neighbour is Rs. 30,875/-. Inspite of both contractor's same estimation, my neighbors refuses me to pay Rs. 30,875/- and instead argues with me and says she will pay only Rs. 16,000/-. Whenever, I talk to my neighbour, she abuses me and says whatever you want to do you can do, she has lot of influence in government offices and no one will stop her from constructing but i will pay only Rs. 16,000/-. She is producing her calculations and is stick to that. Since she is a lady I am not able to argue further. I ask her that i need to talk to your husband, but she does not allow him to interfere in this matter. I tried lot to convince her but she sticks to her decision in an arrogant manner and creating tantrums of being woman and threatens me of harassment case. This is disturbing my family's peace. What should i do in this case so that i will get my full payment of common wall? or should i bring stay? Pl. advise me on this matter.