To expand on what belodion commented on - Android doesn't release for individual phones directly, the phone manufacturer releases the updates for the phones it has released. The "beef" is with Samsung but with a 3+ year old phone it is HIGHLY unlikely as until only recently even Google didn't provide platform updates for its devices after 2 years.
I'm sure the helpful folks in this forum section can help you find a 3rd-party ROM for your device but keep in mind that it is not an official Samsung release.