Purple line down one side of Samsung Galaxy S7 Active

So I have had my S7 Active for 6 months now, and it has developed a thin purple line down one side of the screen.

The problem seems to be intermittent, fixed temporarily by either touching the top right of the screen, going into the screen calibrator, or rebooting. Whatever method is used, its will come back at a random time in the future.

I have seen many posts elsewhere with people having the same issue, and the only recourse so far has been to send it back to Samsung . However, people are reporting the phone comes back then starts the same issue a little while later.

I don't know if Samsung are sending a refurbished unit back with the same stock problem or repairing the original, but if the former I was wondering if anyone has had permanent success with replacing the screen and/or digitize?

Thanks

SAL