I blunder in transaction with a part of Africa (6,5)
I believe the answer is:
sierra leone
'part of africa' is the definition.
(I know that Sierra Leone is part of Africa)
'i blunder in transaction with a' is the wordplay.
'blunder' becomes 'err' (to err is to make a mistake or blunder).
'in' means one lot of letters goes inside another.
'transaction' becomes 'sale' (sales are a type of transaction).
'with' is a charade indicator (letters next to each other).
'a' becomes 'one'.
'i'+'err'='ierr'
'ierr' going within 'sale' is 'sierrale'.
'sierrale'+'one'='SIERRA LEONE'
(Other definitions for sierra leone that I've seen before include "West African nation" , "W. African republic" , "West African country, capital Freetown" .)