Damaged phone

Last week Thursday, I bought a phone from CNA after the phone I as using just stopped charging.

Upon signing my receipt of this phone, I was told that I can bring it back after 7 days if I find a problem with it, or if something is wrong with the device. Around 22:30pm on 13 Dec 2017, the screen went white, making it impossible for me to send texts or answer calls. Keep in mind that this is a phone I've only had for 6 days.

Yesterday I drove back to Sandton to try and sort this issue out. When I got there, I was told that my 7 days is up, and that they now had to take it in for repairs. As far as I'm concerned, the first 24 hours is the same time next day, and not when I put my signature down on that paper. I am now expected to sit without a phone for the next 21 days (minimum) without a phone. That means I must buy a 3rd phone - just so that people can get hold of me - while the phone I bought 7 days ago is gone for 21 days?

I truly think your counting system and your policies are flawed. CNA has offered the worst service of goods I have gotten in years.