That's AWESOME support from them.
I bought a Renogy Wanderer PWM charge controller and after a few days it failed.
I used the Amazon support feature and was connected to a Renogy support person via email
techsupport@renogy.com.
They asked me for some voltage measurements, photos and eventually I sent them a video of the situation.
https://youtu.be/XD-HdRo-sfc
After that, they went silent. For weeks. I kept trying to get their attention.
A few days before the Amazon return period expired, I packed the whole setup up and returned it to Amazon.
TWO DAYS after the Amazon return period expired, I got a message from Renogy asking for some more photos of the unit.
So....... As they say, Your Mileage May vary.
I replaced it with a TopSolar charge controller/panel for $65 and it's been perfect for my needs.