Withdrawing from the case (9)

'withdrawing' is the definition.
The answer and definition can be both to do with contact as well as being present participle verbs.
Maybe there's an association between them I don't understand?

'from the case' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is present in the answer.
'case' could be 'pack' (packing is a kind of casing) and 'pack' is present in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?