OnePlus India — Mobile phone quality related

Dear sir
I m using OnePlus Nord ce 12gb verient. But it's working like 6gb, and camera quality is very poor, video quality also poor.
I bought it through emi in rs.27000/- with instant discuss of rs.1000/- with extanded warranty and insurance of rs.4500/- also.
But I m fool.
There is no quality in this model.company become us fool.
Pls help me.
What I do. I dissatisfied with quality.