Independent’s new head of telesales? On the contrary (4)
I believe the answer is:
isnt
'on the contrary' is the definition.
('isn't' may be said to dispute a claim)
'independent's new head of telesales?' is the wordplay.
'independent's' becomes 'i's'.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'head of' says to take the initial letters.
The initial letter of 'telesales' is 't'.
'is'+'n'+'t'='ISN'T'
(Other definitions for isnt that I've seen before include "Is not (colloq.)" , "In the present, not to be" , "Tins (anag.)" , "Ain't" , "- - This A Lovely Day? (song)" .)