Country getting first-class return on its capital (7)
I believe the answer is:
tunisia
'country' is the definition.
(Tunisia is an example)
'getting first-class return on its capital' is the wordplay.
'getting' means one lot of letters go next to another.
'first' becomes 'a'.
'class return on' becomes 'tunis' (I can't justify this - if you can you should believe this answer much more).
'capital' suggests taking the first letters.
The initial letter of 'its' is 'i'.
'tunis'+'i'='tunisi'
'a' after 'tunisi' is 'TUNISIA'.
(Other definitions for tunisia that I've seen before include "African republic on the Mediterranean coast" , "As Inuit visits there in North Africa" , "Country between Algeria/Libya" , "Land" , "N African country in which ancient Carthage lies" .)