1. Write to the BANK which is reflecting 12597 as the balance and demand to rectify it immediately if there is no Balance.
2. If you are a salaried Employee, then you can approach the Banker where your Salary gets deposited and NEGOTIATE with them.
3. If you are Self Employed Businessman, then approach the bank where you regularly deal.
During Negotiations, if things are going against you, you can get a GUARANTOR for the LOAN [Provided he has Clean History] If all things Fail, go back to the Bank which have reported as "Written Off" and ask for a new deal where they will report the A/C Closed and remove the Written OFF Remark.
Desperately don't go on seeking LOAN as it will get reflected on your Credit Report. Even after settlement with the Banks to get rid of "Written OFF" status, new loan approvers will become suspicious why this man is so desperately seeking loan and why was he denied ?