Purchase of Redmi Note 3

I have purchased 2 Redmi Note 3 smartphones from Hi Fi Corp Mall @ Carnival branch in Brakpan. The first device was faulty and exchanged for another new device. The second device was also faulty (internet connection issues) I returned it to the abovementioned Hi Fi Corp on 11 October 2017 , whereupon it was sent to the supplier MIA Africa for evaluation. They found no fault and scratched my phone , which I noticed on collection (25th October) I took the phone back to Hi Fi Corp on 26th October 2017 , it's was scheduled to be returned again to MIA Africa for re evaluation. I have still not got my phone back. Palesa and Raymond in the customer service department at Hi Fi Corp have really given me very good service. However this needs to be dealt with at a higher level in order to get MIA Africa to do right by me.