i took it in after 350km and showed the screen blush rough around led displayed characters. Two dealerships and the only suggestion was turn OFF the display if i didn't like it. Go figure customer service at Mazda.
Also "Carcarenut" is a utube Toyota Lexus certified mechanic, he said his dealership and others always ises the cheap oil and charges full synthetic. And customers complain engines burning oil in 3 years. Now we take our own oil in for them to add. No cheaper. 7000km and 2nd oil change and oil looks dirty. Maybe turbo cooking it.

 

Are you out of warranty (not sure what after 350km means)? If not I would go in and ask them to show you another one on the lot with the same screen and see if it looks the same. Or call Mazda corporate. They can sometimes help.

As far as the allegation about oil, I suppose even if you bring your own oil in you don't really know unless you get to watch them physically pour it into your engine. Doing oil changes at home is the most assured way to know.