Chosen Solution

theres a black line down the left side of the screen and I need to replace it.

It’s under warranty. Take it to Apple!

Ouch! Sorry you got a bad display ;-{ Have you tried locating the needed part yet? So far whats available is quite expensive! Retina MacBook Pro 15" Complete Display - Silver $1,232.60 US. I would recommend you see what Apple charges for a replacement. If you have Applecare + before you go in it will be cheaper <hint!> AppleCare+ for Mac “Coverage for up to two incidents of accidental damage, each subject to a service fee of $99 for screen damage or external enclosure damage, or $299 for other damage, plus applicable tax”