Equity mortage from bank - get it released

sir, i had availed a home loan with a nationalized bank few years back .. and i just recently paid it off... i did had few disagreements with the bank during the course of this loan on some charges..and we then got it sorted out. the bank had me register for a equitable mortage at the time of the loan disbursal which i did. now i wanted the bank officials to come to the register office to get that charge cancelled as i paid off my loan so that the property will be free of encumberences . but they seem to purposely delay the process...for the fact that i had disagreements with them in the past. how do i take this forward ...is there a higher authority that could get involved on this.... i just cant let this process go as this will show in my EC certificate