Screen showing pink lines

I have been using it for my office stuff

And from last 3 weeks it's screen isn't working perfectly. All i have traced the issue was with the left display cable that goes in between the screen and keyboard, the people over Internet and repairing shops are saying to get it repaired by apple they are repairing their mess for free because they made it that way

Now anyone please tell me how to beg for it and from where should even get in touch .

Thanks in advance