Poor customer service

I did an upgrade from iPhone to Samsung with Vodacom Clearwater mall. After loading the apps and creating the Samsung account the phone worked fine for a few hours then started switching off and restarting on it's own, multiple times during the day. We tried resetting the phone and updating the software but nothing worked. We then went back to the store for them to check, they advised us to take the phone to the Vodacom repair center in Fourways, they did not specify that the repair center is at a different location than the Fourways Mall store. The Fourways Mall store sent us back to Vodacom in Clearwater Mall as he advised that Clearwater store keeps sending customers to them but they do not do the repairs and it had to be booked in for repairs by the Clearwater mall store. We then took the phone back to Clearwater mall, they booked it in for the repair center to check which took 3 weeks (all they did was update the software again and left the phone on for an hour stating the problem is not occurring any longer). Clearwater mall gave us the phone back yesterday 3 April, but the problem started again in the evening, it switched off and restarted again multiple times since last night until now. We then called Samsung today (4 April 2024) and they said that there is no trace that Vodacom did any repairs on the device and maybe only did a software update. This is a brand new phone and has given us endless problems, Vodacom is holding us to the contract but are not fixing the issue we have. It has been a month and we are unable to use the hone at all yet we are required to pay for it. No one gets back to us, if we don't call for feedback, they don't inform us of anything. This is unacceptable, as we have given them 3 weeks with the phone and they are not helping us. This is terrible customer service and a very disappointing experience as I have been a customer with them since 1999.