Still providing office materials, they say (10)
I believe the answer is:
stationary
'still' is the definition.
(thesaurus)
'office materials they say' is the wordplay.
'office materials' becomes 'stationery'.
'they say' indicates a 'sounds like' (homophone) clue.
'stationery' sounds like 'STATIONARY'.
'providing' is the link.
(Other definitions for stationary that I've seen before include "Fixed" , "Static" , "Parking" , "Not moving" , "Motionless" .)