Poor customer service, violation of customer rights

I bought a new phone on the 28th April 2020, within a period of less than seven day the was started freezing when you answer phone calls and accessing other Apps, took it back on day 7 they refused to take the phone and I was told customer service is not operating during level 4 of lockdown. I feel my rights as a customer were violeted. Because they were support to refund me or give me another phone. I blame Neville from that store, as I had to us them to give me something in writing that I came to the store complaing about the phone within 7 days, the only thing he did was to sign the back of my till and wrote no exchange at the moment after the lockdown, the unfortunate part isn't that I had to come back to Johannesburg on that day, since people were allowed to go back to their places withing the 7 days period. With my big tummy I went to game cresta they could not assist me they referred me back to game amanzimtoti. The phone is even worse now compared to before. I received poor service and I've been given a run around. I want my money back. At the back of their till slips it says"we offer peace of mind". The only thing I got from them is endless stress, waste of my time and money. I regret buying phone from their store.