Vivo Y27s "UNIT BURNED WHILE ON CHARGE NOT CLIENTS FAULT"

So I bought a Vivo y27s mobile phone from Vodacom South Africa. After using it for a few months, it burnt out while on charge!

I took it to the repair centre in Vanderbilpark, Gauteng who in turn sent it in for testing. When they returned my phone the Reported Fault reads as follows: 13 - POWER PROBLEM,CHARGING PROBLEM - INTERMITTENTLY NOT CHARGING, POWER PROBLEM - NOT SWITCHING ON / OFF / SHORT BATTERY LIFE, UNIT BURNED OUT WHILE UNIT WAS ON CHARGE - NOT CLIENTS FAULT

So, after contacting Vodacom and asking what I should do, they suggested that I take my phone in again and escalate the situation.

After taking it back for a second time... It was again returned saying REJECTED! And a quote of R4828.85 to replace my phone.