MACBOOK AIR M1 Purchase from MTN

Dear MTN I bought a MacBook Air M1 from MTN Tygervalley shop at the beginning of March. After the use of the laptop for +/-2 weeks, a black line appeared on the LCD Screen. I contacted MTN immediately and they advised me to return the laptop with box and charger to MTN ASAP. I returned the faulty laptop to MTN on 19 March 2021 which was 3 weeks ago. MTN then booked the laptop in at iStore who confirmed that the screen / unit is faulty. STILL NO REPLACEMENT UNIT OR ANY CORRESPNDENT FROM MY MACBOOK AIR M1 unit. This is unacceptable since I only had the use of my laptop for +/- 2 weeks, and it is taking this long to get it sorted out. Nearly 3 weeks. I cannot be without my laptop any longer. I am losing income as I am the owner of IT Business and need a computer to run my business. VERY BAD AFTER SALE SERVICES, I WILL NEVER PURCHASE A MACBOOK EVER.