Help Regarding Black Lines Display Issue

Hello everyone, I have bought my Macbook pro 13 inch almost a 18 months back and right after 2 months of buying, I got a cosmetic damage of the plastic area of the bottom of the top lid (as shown in picture). It happened because, I closed the lid and accidentally the headphone jack went in between and got the crack. I have spoke to this about the design issues with applecare team even before buying the applecare protection plan from the local apple dealer. (I have those email transcripts with me). According to them, there were no problem and no hardware issues detected that time.

Now its been almost 2 weeks that I am having some issues with the display as well as the keyboard. Display is showing black lines and bars when the laptop is getting heated up and shown clearly on the picture attached. Problem with the keypad is about the keys are getting repeatedly typed automatically and some letters are having some small issues.

Now, I am worried about the cosmetic damage which I had long back and does apple provide me a coverage under the applecare protection plan for the display?

I am 100% sure that the damage didnt cause anything to the display and its just affected the external plastic part. And the display issues seems to be a common one, came to know about this from forums.

Can someone please help me what to do? When I took it to a service center they asked me to contact Apple for this and I dont know what to do next?