What should I do to make sure I get refund through ECS?

The applicants are required to ensure that bank details including MICR code (9 digit code which appears in the cheque) maintained at the depository level are updated.

If you are not getting refund, check the bank information you provided in your IPO application form. If you are applying IPO's online though an online stock broker, make sure that he has correct information of your bank account.