Dell customer support

I purchased a New Dell end of 2015.  June 16th 2016 the computer started having problems with the display - called Dell on 6/22 said they don't have the parts - finally after 2 more calls I got the parts sent with a technician on 7/1.  The new parts didn't solve the problem so I was given another number to call for support.  They referred me to different departments 8 times - each technician doing something else to my computer on 3 occasions when I called them - doing the same thing over and over -even after the so called "fix" and it still isn't working - so spent another 4 hrs. on the phone and finally after 8 transfers, speaking for 3 more hrs. to different agents, telling me to call another number 7 items - the last number says - "all agents are busy - call back later - click!"  I just want my computer fixed - and this has been a nightmare - each time they have me trying the same thing over and over - on the same service ticket - why?  I've spent a total of about 8-10 hrs. on the phone plus the service call and the last call "All agents are busy, please try again later" click.  Dells customer service is terrible - does anyone have a suggestion on how I can get it fixed, its under warranty.