on the contrary
US /ɑn ðə ˈkɑntreri/
UK /ɑn ðə ˈkɑntreri/

1.
al contrario, por el contrario
used to intensify a denial of what has just been implied or stated by suggesting that the opposite is the case
:
•
“You didn’t like the movie, did you?” “On the contrary, I loved it!”
“No te gustó la película, ¿verdad?” “Al contrario, ¡me encantó!”
•
Some people think he’s arrogant, but on the contrary, he’s very humble.
Algunas personas piensan que es arrogante, pero al contrario, es muy humilde.