From The Enigma
NPL Magazine - Feb. 2015
LEXMAN

The two answer words to this flat are heteronyms - words which are spelled the same, but pronounced differently - without any change in stress or syllabication.

Your gift was in poor taste, so I
     returned it.
I _ _ _ _ _ _ that, in response, you
     simply _ _ _ _ _ _ it.

Answer:

RESENT (S has Z sound)
RESENT (S has S sound)