Android updates are far from simple. There a ton that goes on to make them work.
The short version is your mobile network provider is probably the reason you didn't get it over the air. Telling them won't help, they probably don't even realise.
Google makes an update, samsung makes it work on the devices, the cell carrier approves the update, the phone accepts the update.
Usually the cell carrier approving it goes wrong or the phone accepting it, though the phone part can usually be sorted by a reboot, cache clearing or starting the download on mobile data.
Because of how bad the system is, google added a second update system called google play system updates. The main update system is kinda a relic from the times when cell providers ran custom code on phones
