Vodacom Disgusting Service

We bought my mom a Galaxy A03 Core Cellphone in August 2021 from Vodacom in Musgrave Centre. Within that same month the phone stopped working. It got very hot and just went dead and wouldn't charge. We took the phone in to Vodacom at Musgrave Centre and they plugged it in and it worked. They told us that our charger was obviously not plugged in properly. Since then we have taken the phone in another 3 times for the same thing and every time when the sales person at Vodacom plugs in the charger it works. It seems like the phone overheats and only comes back on when it has cooled down. We were told by the sales person that if they send the phone in for repairs the technicians will not check it if it comes back on. She also said that this happens with these phones often. If this is a recurring problem then surely the phone should be replaced. We have been ****** by Vodacom as we have paid for a dud phone and they refuse to do anything about it.