Charity returns laptop and phone (4)
I believe the answer is:
dial
'phone' is the definition.
(dial phone is a kind of phone)
'charity returns laptop' is the wordplay.
'charity' becomes 'aid' (eg foreign aid).
'returns' says the letters should be written backwards.
'laptop' becomes 'l' (top of the word 'lap').
'aid' reversed gives 'dia'.
'dia'+'l'='DIAL'
'and' is the link.
(Other definitions for dial that I've seen before include "Indicator" , "Face of a timepiece" , "Clock face" , "Ring the clock-face" , "Meter face" .)