Severely punished, did well to hold firm (8)
I believe the answer is:
scourged
'severely punished' is the definition.
'scourged' can be an answer for 'punished' (scourging is a kind of punishing). I am unsure of the 'severely' bit.
'did well to hold firm' is the wordplay.
'did well' becomes 'surged' (I am not sure about this - if you are sure you should believe this answer much more).
'to hold' means one lot of letters goes inside another.
'firm' becomes 'co' (a firm is a company).
'surged' going around 'co' is 'SCOURGED'.
Can you help me to learn more?
(Other definitions for scourged that I've seen before include "Go cursed to be flogged" , "Whipped or afflicted greatly" , "Thrashed with whips" , "Plagued" .)