Blank Cheque given to bank.

I had an existing loan with HDFC which I tried to transfer to ICICI because they were offering a lower rate of interest. But due to incomplete and incorrect information given to me by ICICI bank representative I decided not to transfer the loan (continued with HDFC), Now ICICI wanted me to pay some charges for cancelling the transfer which is Rs 11.313/- (Broken Period Interest= 6139, Cancellation Charges= 3450, Processing fee= 1724). The DD for the loan amount given by ICICI was delayed which created complication(HDFC EMI deducted, ICICI EMI Due in same month, Foreclosure amount). The DD was issued on 28th Dec but the DD was given to me on 5th Jan. I went back to ICICI bank and handed over the DD back requesting cancellation on 11th Jan. The manager didnt initiate the cancellation and delayed it further. Now they want me to pay the Broken period interested for 35 days (from 28th Dec till 31st Jan). I informed them I will pay only the cancellation fee Rs 3,450/- + Broken Period Interested for 7days I had DD with me Rs 1227/- Total Rs 4677/- Now they are threatening me that that this will become a court case. I have all the conversation in written (email). Please suggest me my options to get out of this hassle and also want to know will they use the blank cheque I have given them?