BAD CUSTOMER SERVICE

I bought a Samsung cellphone from Truworths Mall of the North on the 01/06/2021 and it stopped working on the 21/06/2021. I then took it back to the shop and was told that they can't replace the phone but have to send it for repairs and will take 21 days. I told them that I'm using the phone for business and cannot wait that long but was told that it's their procedure. I feel that they are failing us as customers cause how can a phone have to be sent for repairs within a month of buying it. Which means their product s are not good or proper and now the customers have to suffer. The manager kept on telling me what must she do because she's not allowed to replace the phone. I just feel that they don't care about their customers as long as they making their sales.