Help random pixels on screen when stuff changes

[shovenose]

I'm having a weird problem that there are random colorful pixels on the screen and it also randomly glitches completely with the "new in open box" HTC one M8 (T mobile edition) that I just got from eBay. I first noticed it when using the camera. If you look carefully, you can see the random colored pixels in my video (that I took with my HTC 10), though it didn't have any major graphical glitches. Any suggestions besides returning the phone? I literally just finished setting everything up on here :'(

example of issue:

 

[Mikestony]

Moved to the M8 forum per your request

 

[shovenose]

Moved to the M8 forum per your request

thank you sir

 

[shovenose]

ok well done some more testing and definitely defective. seller sent me pre-paid shipping label and i am returning it.