Yes, Airtel wont do that. They want to earn max and offer these packs only via marketing channels. The topic link that i provided has brochures (provided by DDF user @
kathir) that clearly show the pricing on annual packs, but callup airtel, they will clearly say they have no clue and will deny even these packs exist and will only help you with self-care packs and none outside that.
They just want to offer these to newer users and have no intention to offer the same to existing users as they cant generate additional income from current users.