Shocking policy and customer service re cellular phones

I bought a Netsurfer Tomcat from the Mall of Africa branch on Sunday 01 July 2018 . Within 3 weeks the phone stopped charging, so I took it to the Atterbury branch on 26 July 2018, expecting to get a replacement. I was told there would be this lengthy process, up to 21 days, before getting the phone replaced/repaired. It is now 10 August, and I've been told the phone was only collected from the branch on the 1st August... and nobody can give me an ETA, only that it will now take up to 21 working days from the 1st before I have an answer. This is unacceptable, I am about to lose my job because my employer cannot reach me at critical times and Ackermans can't get the customer service together. Surely a phone that is less than a month old that clearly has no physical damage to it, but has stopped working should automatically be replaced? Even so, 26+27+28+29+30+31June+01Jul is seven days from the time the phone was returned, to reach the service centre... unacceptable. My job is on the line!!! Please sort this out. It only cost R800, and I swear I will do Ackermans a lot more publicity damage than that... if my constant bickering to fellow staff and management at my employer has not done so already. PLEASE!!!