If an amount of settlement and date of payment was stated in decision and you have complied with decision of the Lok Adalat then apparently you have fulfilled your obligation. However the decision of Lok Adalat, acknowledgment of payment issued by bank, and all communications exchanged by you with bank should be carefully studied.
Did the bank issue NOC after you made the payment.
If there is communication from your end accepting any shortfall in the payment from your end and 3 years have passed then it could be declared time barred.
You may immediately withdraw funds from all SB a/c’s and close all SB a/c with the bank. You may also obtain latest CIBIL report and check if bank has updated your record with CIBIL after the payment or not?
It shall be appropriate to show decision of the Lok Adalat, NOC and all communications exchanged by you with bank to a competent and experienced lawyer specializing in such matters and reply to the notice as per expert advice.