Sad return about service repairs (5)
I believe the answer is:
darns
'repairs' is the definition.
(darning is a kind of repairing)
'sad return about service' is the wordplay.
'return' is a reversal indicator.
'about' means one lot of letters goes inside another.
'service' becomes 'RN' (abbreviation for Royal Navy).
'sad' written backwards gives 'das'.
'das' going around 'rn' is 'DARNS'.
(Other definitions for darns that I've seen before include "Mends (a hole)" , "Sews" .)