The Copper Bullets entered the competition as defending champions and one of the favourites to lift the trophy again, but fell at the first hurdle by losing to eventual champions Namibia on penalties in the quarter-final.
After being relegated to the Plate section, Chipolopolo beat Ghana before losing to Malawi in the Plate final to return home empty-handed.
Janza admitted the side's performance was not good enough, but remained adamant they had learned important lessons from the competition and was confident they would qualify for the 2018 World Cup.
"It's a painful situation here that as Zambia, we walk away with nothing; but I can only say that we will come back.
"Soon you will see a team that will qualify us to the World Cup. Don't be afraid, it will happen.
"We know where we are coming from and where we are going, we are not far from it. It's within our hands; we are on course."