Gurantee

My father was director of a company he signed personal guarantee in June 1995 but resigned from company by October 1995, loan was released by bank in February 1996 after my dads resignation. My father passed away in 2003. After so many years bank is coming after us they have filed case under sec31aa of SFC act and attached properties of legal heirs of my father. My father did not receive any legal notice during his life time nor did we receive any. Wat defence should we take is case barred by limitation. Any one please help or guide me. Thank you.