Chartered Accountant in condominium sadly unable to be contacted (13)
I believe the answer is:
incommunicado
'unable to be contacted' is the definition.
(not able to be communicated with)
'chartered accountant in condominium sadly' is the wordplay.
'chartered accountant' becomes 'CA' (abbreviation for chartered accountant).
'in' means one lot of letters goes inside another.
'sadly' indicates an anagram.
'condominium' with letters rearranged gives 'incommunido'.
'ca' put inside 'incommunido' is 'INCOMMUNICADO'.
(Other definitions for incommunicado that I've seen before include "Uncontactable - in solitary confinement, perhaps" , "Out of contact with other people" , "Unable to talk to others" , "Beyond contact" , "Held without contact" .)