Uninstalled app coming up in update list in play store

I uninstalled an app using a long tap shortcut that comes on One plus two mainscreen, which I guess is also the time when there is an update waiting for this app because the next time I opened the Play Store, an update shows up for the app. When trying to update and then uninstall (this time from Play Store), it still keeps showing up in _Updates_ list and the whole things repeat. The app is _Swiftkey Keyboard_, if that helps. Any recommendations on permanently removing the app would be helpful. Android v6.0.1, OS: OxygenOS v3.0.2 * I tried *Settings > Apps* and there is no uninstall option, instead there is a disable option next to force stop. In play store, there is update option which doesn't help as I stated earlier. * I doubt if it is a system app, because I voluntarily installed it (from Google Play Store as I remember; I enabled installation from unknown sources only after the release of Pokemon go, I am not aware of any other possible ways of side-loading) * The app doesn't show up in *Device Administrators* (there's only Android Device Manager and another paid app visible in device administrators) * I disabled it, it stopped showing up in updates, keyboard menu and elsewhere, but it still is taking up that internal storage as shown in *Settings > Apps.*