I am a disabled person, do i need to pay the outstanding.

You may go thru many threads on recover agents and pick up relevant points:

https://www.lawyersclubindia.com/forum/Harrasment-by-icici-banks-recovery-agents-76271.asp#.UUc5U0pFZ_4

https://www.lawyersclubindia.com/forum/Standard-chartered-and-shaha-finlease-95120.asp#.Utl35tK6a3Y

https://www.lawyersclubindia.com/experts/Credit-card-problem--446451.asp#.Utl4H9K6a3Y

https://www.lawyersclubindia.com/experts/Credit-card-defaulter-time-limitations--446061.asp#.Us7ig9IW1MA

https://www.lawyersclubindia.com/experts/Credit-card-debt-448106.asp#.UvpMrEeBmXU

https://www.lawyersclubindia.com/forum/Standard-chartered-and-shaha-finlease-95120.asp#.Usvvc9IW1MA

https://www.lawyersclubindia.com/experts/Credit-card-payment-443961.asp#.UsvwjNIW1MA

https://www.lawyersclubindia.com/forum/Credit-card-robbery-fraud-in-china-94830.asp#.UsvwUtIW1MA

https://www.lawyersclubindia.com/experts/Harassment-by-recovery-agents--442841.asp#.UrhGa9IW1MA

https://www.lawyersclubindia.com/forum/Salary-account-freeze-without-my-notice-95425.asp#.UswXWNIW1MA

https://www.lawyersclubindia.com/forum/Standard-Chartered-Bank-Sold-My-Banking-Credentials-to-Shaha-39265.asp?1=1&offset=2

https://www.lawyersclubindia.com/forum/Mental-torture-and-harassment-from-axis-bank-recovery-agent-103820.asp#.U6Ev5ZSSwb8

NO one shall believe an agree that you were disabled due to calls.................................

If you can prove it...............................you may have some edge.

'Written Off' is an adverse entry and shall affect your credibility, credit rating..............................don't go for it.

Prove the deficiency  in a form e.g. Consumer Forum, obtain order to clean your credit history and waiver of penal charges, and penalty on M/s SBICPSL/SBI Cards................................