Display line burned and frozen KPA/Remote

I have the KPA for 4 months and the remote for 1 week. Everything always worked.
Turning on my KPA this morning it didn't work correctly, it was kind of frozen and the remote wasn't working at all. A line on the KPA display was (and still is) blank (see picture)
I was on OS 4.0.0
I did a system reset with no success and than a flash memory erase.
I upgraded to OS 4.0.1 and rebooted. Restored my backup.
Still the remote was giving the "WAITING FOR CONNECTION" for minutes, i rebooted than it started blinking like a Christmas tree with a weird image on the screen.
I rebooted two times and now it seems it works. The display on the KPA seems burned forever.
In less than two weeks I start playing live every single day for four months, I'm a little scared to rely only on my KPA, it doesn't seem reliable, and I always treated like a little baby, maximum care.
Anyway now I would fix the display, anybody had to return the KPA for fixing? How long do they take to send it back?
I wrote to the support, just had the answer, it's a hardware problem and I should send them the KPA.

Quote from MtotheEikel

The first thing I'd do if I had to pay live every day is downgrade to a release firmware.

I tried the beta only because I'm at home for some weeks and have the time to check if it is reliable, if not I switch back to a release. I was unhappy with the OS 3.2.1 that I had for months. The bugs are also in the official releases, and I hoped in a better quality of the fx.
I don't think anyway that a beta can burn lines on the display.