Extremely bad service from vodacom

I have purchased two Samsung J1 phone from clicks the workshop branch. The phone keeps on switching off all the time. I had sent the phone for repairs and they had taken days to get back to me and said there's a problem with the battery. Now the phone keeps on switching off again. I'm tired of this. I want my money back , I rather buy another phone. Vodacom tried only once to contact me and after aftet thay they never bothered to.