But think about it - No site will become "Proven reliable" until someone doesn't follow your rule. I think OP did a great job testing out a new site.
https://gaming.youtube.com/channel/UCYDJr392l7gA7HDh9uJVkkw
https://en.wikipedia.org/wiki/Agar.io
The thing is, the game isn't provably fair. It's simply luck and skill. Unless of course, the OP isn't lying and his balance started going down randomly. Looking at their thread, they have refunded a guy already for some weird error. Not sure why OP hasn't been refunded, though.
Why testing in a new site? Not in primedice or bitsler which is proven reliable? Let other people risk the money, why I try? I don't wanna risk the money to test a scammer, it is my 2 cents.