iPad Pro 10.5” display problem

Hello, I’m writing here because I don’t know what should I do.

I bought an iPad in April last year in Cortland (Apple Premium Reseller in Poland). Everything was good till November - then I noticed some strange white spots on the display. I did some research and send my device directly to the store - they accepted my request and replaced it with the new one. I thought the problem has gone, but not this time.

At the beginning of January I noticed some green lines on the top edge of the screen. They are not like bad pixels, because they are moving every time I’m moving something on the screen (like apps, or just multitask).

I’ve read on the Reddit that might be a software bug, so did I download and install the new software from the iTunes. Nothing changed. I did nothing bad with my iPad (like throwing, or beating), I always have it in my case.

What should I do? Should I send my device to the Cortland service one again? It is getting on my nerves that I pay so much and I get such a problems with that device.

If it would be possible I would go for a refund and get other device to work with on my daily basis in school.