ICICI Home Finance — unathorised withdrawl of EMIs

The ICICI Bank took a post dated cheque for payment of EMI towards loan repayment for Rs.10, 157/-After a few days they again approachedd saying that the interest rate had been revised and as such a fresh cheque was required for rs.10, 766.
Instaed of returning the previous cheuq they have used both the cheques and withdrawn EMI twice for the same month.The query to them remians unresolved