Review Bought a Techno Camon 12 Air that is really frustrating

Bought a Techno Camon 12 Air about on 22/06/********. On the pack and on phone settings it shows it has 64GB internal storage but it can hardly take a simple application of 21MB, it says memory is full.
It is quite frustrating.
I tried returning it to teh seller, and she said she has no control since she could also read what is on the phone says.
I tried calling all the customer care phone lines o techno customer care i Nairobi and none goes through.