Poor service delivery

I bought a Mac book 4 laptop 2 months ago and the charging cable just stop working a mont ago. I went to Menlyn i store and they just want to sell a charging cable to me. My laptop still under warenty. Then they refer me back to Brooklyn i store where I bought the laptop. Brooklyn did not have stock to replace the cable. They told me 2-3 wotking days. After 7 working days I complain on a e-mail. They said 7-10 working days. It now has been 20 working days. No charging cable. When I complain they said I can come and buy any cable but then there is no warenty and I pay for the cable that cist R1600. How can this take so long. Why do you sell a product but do not have spares to help the customer. I think I waited long enought. I cannot work. And you can only do so much from your phone. My boss does not believe me that i store cannot solve the problem in 3 weeks!!!