Macbook Screen Graphics Glitching From One Frame To Another
Take it to an authorized apple repair facility.  They are the only ones that can get new parts.  The labor is reasonable, $75 an hour if I remember right.  You can try and go with a used screen but you're taking your chances.  If you have apple care then they might replace the screen for free.  I can tell you that the retina screen is about $450 on a MacBook.  They will also do a free diagnostic to make sure the quote is accurate.  Looking on Amazon the price is about the same so might as well let the pros do it.

As far as the diagnostic part try plugging in an external display.  If the display glitches there too then it's probably not the screen.  Let us know what happens on an external display.