First ensure two things.
1)The NOC given by the Bank is safely preserved.
2.Bank has not issued any notice, informing any mistake and demanded any payment since the NOC.
Issue a Registered notice seeking information the grounds on which they are demanding repayment of a loan, after giving NOC and without giving any communication to borrower since giving NOC. Specifically inform them that you are treating this as harassment and it amounts to deficiency of service and you will be compelled to resist all such attempts made by the bank.
If you have already received summons from Lokadalat, go prepared with written submissions on the same line that you have settled the account, obtained NOC and there was never any notice or demand from the bank, and that the bank is harassing you even after such settlement.
Depending on further steps of Bank you may respond.