Are called in to put things in order (7)
I believe the answer is:
arrange
'put things in order' is the definition.
'arrange' can be an answer for 'put' (arranging is a kind of putting). I am not certain of the 'things in order' bit.
'are called in' is the wordplay.
'called' becomes 'rang' (called on the phone).
'in' means one lot of letters goes inside another.
'are' enclosing 'rang' is 'ARRANGE'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for arrange that I've seen before include "Set in place" , "Settle, work out" , "Fix" , "Orchestrate - order" , "Put in sequence" .)