Samsung India — inappropriate information provided during purchase of samsung galaxy a805fz

I purchased Samsung galaxy A805FZ on 2/09/2019. I unboxed the phone and inserted my simcard on the same day. While making the first call i realised that the voice which i was receiving was inappropriate and the voice was vibrating like anything. The very next day i went to the dealer and he said that he knew nothing about this. On complaining about the product in the service centre they took the phone from me and kept it with themselves regarding complaint no [protected] dated 03/09/2019. After few days they called me and said that this is a so called technology(which is i not made aware of) as the phone carries an inbuilt speaker under the screen and nothing can be done for this.
The phone was with the HOTSPOT dealer(the place from where i purchased the product) for few days after which i remade a complaint on 14/09/2019 vide complaint no [protected] and the service centre took the phone and kept it with them. The company called me several time saying they will do something and provide me with a new model phone of the same value. But after 3-4 days they called me and said that we cannot do anything and u can collect the phone from the service centre.
I am attaching all the complaints documents and the mails that i got from the company. Please do something so that no other consumer get misguided by this multinational companies