Icici bank harrasment

Hi I had an 2 year old Personal loan running with ICICI which I tried to close this Oct'17 by have a balance transfer from other bank. While taking the loan from ICICI I was cleared told & made signed that there will be no pre-closure charges on closing my account after 12 months. I visited the bank multiple time to to get my account closed but I was told they need approval from their seniors first, it took 10-15 days fro the approval & later they accepted my payment on 18 Oct'17 & I was told that the excess amount will be refunded to me after 10 days. Instead I got a call in Nov stating that the loan is not closed & I have to pay my Nov'17 moth EMI after making him explain he asked me to write to a mail to the bank. EMI for Nov'17 was not deducted but I was told that I'll have to pay-foreclosure charges as bank has changed in policy & they can't give me the waiver. I shoed them the copy of the agreement too for which they further escalated the matter to their seniors. In Dec'17 ICICI deducted the EMI from my account without giving me a solution for my concern, after multiple mail exchange & branch visit they told me to pay the amount else the account will not be closed. In-spite of no fault from my end I agreed on paying the amount, but the team took 2-3 weeks to confirm me the amount. Finally I paid the pre-closure fees & was told details will be updated, but again to my horror one more EMI got deducted today. Please help me how to take this matter legally