Movies are a great way to learn a foreign language and subtitles work wonders to increase reading speed. Especially when they don’t give you a choice to fall back to a dub.
Source: me, having to watch Cartoon Network as a small child with no translation at all, became proficient in English by the 5th grade in a country where English is not spoken at all, other than when being (poorly) taught at school.
So rather than seeking out dubs you should avoid them as much as possible.