Samsung Galaxy Tab S3 10.1 possible LCD malfunction?

My Samsung Galaxy Tab S3 10.1 is having problems with the screen. The digitizer and everything else are all OK, but the icons on the screen are flickering and going all over the place and the colours are really messed up. I've only had it for a few weeks and now this is happening. I don't know if there's a fault with the LCD or the logic board or what, but what I want to know is what the problem is and if it can be repaired or if it is a £300 total loss. It is still within guarantee but the store I bought it from have no advice in the troubleshooting section on their website regarding the product whatsoever, so I'm wondering whether I'm better off driving all the way to the store where I bought it from to find out if it can be done in branch or searching online for somewhere that I know can fix these things. The problems I have with these third party retailers though is that, although they can do the job cheaply compared to the manufacturer, I may void the 1 year warranty so if another fault develops, I'm doomed. Also I run the risk of being scammed if I get it repaired elsewhere.