Bad Quality Samsung A21s device & NO REPLACEMENT

I have purchased a Telkom contract online for a Samsung A21s, which got delivered on the 16th July 2020. I have done a smart switch copying all my data from my previous phone. During the process i have realised that the device is faulty. I have emailed Telkom regarding this and wanted to cancel this contract but no one corresponds back. I am now sitting with this piece of SH_T phone, that doesnt function properly, the sensors on all buttons doesn't work. The phone reboots on its own on barely get signal on the device.

Is there anyone that can help??