HSBC personal Loan
Despite of Settlement ECS was presented

I made my settlement as per the HSBC Bank Settlement letter for Rs. 15, 900/- in two installment (Rs. 10, 000/- & Rs. 5, 900/-) on 27 December. Despite of this the ECS for Rs. 2, 022/- was cleared from my State Bank of Mysore Savings Account. So in this regard the Collection Agent is obliging and he is trying to help me out of the genuine problem. But the bank refused and told that the settlement has been null & void and so there is still an outstanding in my account for Rs. 18, 000 something. So i need help in this regard. Can anyone suggest