Meat product I'm unfortunately returning (6)
I believe the answer is:
salami
'meat product' is the definition.
(I've seen this before)
'i'm unfortunately returning' is the wordplay.
'unfortunately' becomes 'alas' ('alas' is used to express regret).
'returning' says the letters should be written in reverse.
'im'+'alas'='imalas'
'imalas' backwards is 'SALAMI'.
(Other definitions for salami that I've seen before include "Food" , "One kind of tactics" , "Highly seasoned Italian sausage" , "Italian garlic sausage" , "Spicy preserved sausage" .)