Re: well
You didn't install the Messenger app, but did you install the Facebook app or was it included with the phone and not uninstallable?
I bet the first thing it did was upload your phone number even if you had the foresight to disable/uninstall it, and if you decided to leave it there but not log in it's probably still adding to your dark profile, as they call it.
I think it's time each and every EU privacy regulator rip Zuck a new one, the day after the GDPR comes in, except the Irish one of course who knows which side his bread is buttered.