Don't want to fix my new laptop

I have a DELL laptop which is still under a year guarantee. When I took my laptop in to Makro Port Elizabeth to look at it, they booked it in for repairs. The next day I got a phone call saying they can't fix it. Now I'm not sure if it is Makro or Dell's fault. But they didn't even have a look at my laptop to see if they can fix it. According to Dell's one year warranty they are supposed to either repair or replace my laptop. Now I am stuck with a laptop I can't do any internet work on due to Dell and Makro's horrible service. I am so disappointed as this is a new laptop. Dell and Makro should pick up the slack!