Credit Card Settlement

Hi was using the Sbi credit card and its been almost 7 years since the card was terminated, they came for a settlement of Rs.12000 in two instalment, I paid 1 installment and could not pay the other installment, now when I ask SBI for settlement they are asking me to pay Rs.15000.

My question is, is it very important to clear the outstanding or is it fine, will it affect me in the future.