Macbook pro screen flickering issue

Hi, I'm from India, I purchase a MacBook Pro in which I have noticed screen flickering issue which is 15days old laptop. The service team kept the device for 3day and came back that there is no issue and when I went to service center for collecting the laptop I have an encounter flickering issue since from that date to till dates it almost 30days still my laptop is with the service center. They have replaced the logic board twice and display & top board once, still the issue is persisting, There are three Executive Relations EMEIA (Ireland) have got interacted but out of that two executives are out of office, on Thursday (09/08/2018)I got a call from Dino and was told that they are doing to replace logic board and display after that next day I got a call from service team they have ordered a part which they would be getting it on Monday by the same day they going to deliver my laptop, on Monday I have called many times to service center they haven't responded, On Tuesday I got a call from Executive Relations EMEIA and was asking me whether they have to do replacement or not. I was shocked that why he asking about it and I have asked him to provide me with the writing if you couldn't able to rectify the issue, he was denied

Can any help me how I need to escalate the issue its 34days I haven't got my laptop yet?

Being a reputed brand no one is ready to provide a resolution from Apple.