Rang computer department to resign; succeeded and put end to dispute (6,2,5)

I believe the answer is:
called it quits
'put end to dispute' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'rang computer department to resign succeeded' is the wordplay.
'rang' becomes 'called' ('call' can be a synonym of 'ring').
'computer department' becomes 'it' (I am not sure about this - if you are sure you should believe this answer much more).
'to resign' becomes 'quit' (to quit something is to resign from it).
'succeeded' becomes 's' (genealogical abbreviation).
'called'+'it'+'quit'+'s'='CALLED IT QUITS'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for called it quits that I've seen before include "Resigned" , "Brought an end to a venture to prevent further losses" .)
