Defects of iPad pro 2018 11

I bought an iPad Pro 11 in Bangkok in January 2019 (on my birthday)

After two weeks black dead pixels appeal on screen

I changes it to another, but! There was different color of screen and small gradient on the edges. I have no choice and I take new.

But! After some time I see dark spot with white halo. 

I went to Frankfurt and changed iPad to another.

But! Now I have troubles with WiFi connection. It is some times not working and I need to reset Ipad.

And I see that WiFi connection goes low, but my old iPad Air 2 works very good in the same room. When iPad Pro connects to WiFi – speed of internet slower than old iPad.

In addition, the replaced device is careless and worn. Glue bulges out a bit (or whatever)

I very disappointed and don't know what to do with all this situations, because I was spend my time and lot of money to resolve all this problems.

[Edited by Moderator]