Inspiron 17 7000 series 2-in-1, screen distortion

Hello, I bought an Inspiron 17 7000 series 2-in-1 in January 2017 and it had problems starting in February. (so, very very soon after I bought it). 

The main problem (and only problem) is a screen distortion that happens DAILY when I use the computer.

The monitor starts have flickers and black bands, distorting the image and making, eventually, the whole screen black. It happens when I use programs such as Photoshop or video games, but recently it has been happening also when I'm just using it to browse the internet. (So, not under stress like in the other 2 situations.)

The only way to '''restore''' the screen is to block it with the 'lock screen' button on the side and then unlock it again. Then it goes away, but eventually the problem comes back.

I've been downloading drivers for the graphic card, looking for resolutions, I even sent the computer in assistance three time and they didn't find anything wrong. They changed my SSD but the problem wasn't that. I can't figure out what the problem is, even if it is software or hardware.

The computer is not even one year old and I'm extremely concerned about this problem that doesn't seem to resolve. I've also tried to change luminosity, screen resolution, anything, but I can't figure out a solution.

Anyone had this problem? Anyone can help or give some sort of advice? I've lost hope in the assistance honestly, because they already took my laptop in assistance 3 times and the PC still has the problem. Thank you for anyone that will respond.