Terrible Vodacom service

I've had an incredibly unpleasant experience with Vodacom. I received my new Samsung A70 in September 2019. Non stop problems. My screen turns blue and it states that the software is faulty. I then sent in for repairs. I was told it would take 3 days and received my phone two weeks later. They replaced my screen and battery. I don't know why because that wasn't the stated problem. I then sat with the same problem for months on end. Eventually my phone was dying every time I tried to type or use it, to an extent where I felt it would become a security risk as my phone was unreliable. I have just taken my phone in again. Again stated that it was software as the blue screen shows. +-21 days later and my phone is still doing the same thing. I pay R600 a month for a phone that I can't use. Vodacom politely told me that they aren't worried if the lose a client. Everyone Is willing to assist when you going to spend money but no one knows anything if there is a problem. I've asked for them to replace my phone and they won't. So what now ?