Old Zambian Kawacha still exchangeable ?

I was looking at some old Zambia kawcha Bills on numista when I noticed they had a exchange value. some but not all of the old first kawcha banknotes had exchange value( very little ) but still nominal. I can't find any where if this bills are still being traded in so Im really confused

I did a little checking and it looks like the exchange period ended January 1, 2016. I don't know if they might have extended it subsequently, though. The Bank of Zambia website doesn't seem to mention it.

http://www.daily-mail.co.zm/change-old-notes-now/