Called in a long time back to put in order (7)
I believe the answer is:
arrange
'put in order' is the definition.
'called in a long time back' is the wordplay.
'called' becomes 'rang' ('ring' can be a synonym of 'call').
'in' means one lot of letters goes inside another.
'a long time' becomes 'era' (I've seen this before).
'back' shows that the letters should be reversed in order.
'era' back-to-front is 'are'.
'rang' placed within 'are' is 'ARRANGE'.
'to' acts as a link.
(Other definitions for arrange that I've seen before include "Dispose" , "position" , "Bring about or put in order" , "Put in order; plan" , "Settle, work out" .)