Went off a bit, but had something done about (8)
I believe the answer is:
departed
'went' is the definition.
('depart' can be a synonym of 'go')
'had something done about' is the wordplay.
'had' becomes 'part' (I can't justify this - if you can you should give a lot more credence to this answer).
'something done' becomes 'deed' (a deed is something done or performed).
'about' indicates putting letters inside.
'part' placed into 'deed' is 'DEPARTED'.
'off a bit but' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for departed that I've seen before include "completely breathless" , "Quit" , "Dead; set off" , "Left, went away" , "Gone, maybe dead" .)