Cellphone Upgrade

I Upgraded my to a Samsung galaxy A20 on 18/06/2019 , the phone started malfunctioning in its first week . I took the phone back to the MTN Jacaranda store a couple of times between 21/06/19 and 30/07/19 due to the issues I was experiencing, the phone was automatically switching on "talkback" without any user intervention. the phone was reset to factory default a few times by the store reps but the issue still persisted. The phone was then sent to HVRC Midrand to be checked (I as given proof of this) . I was then informed that the phone had a major flaw and that i will be receiving a brand new phone. I use this phone for my business, Please assist urgently