Ah, the wonderful world of gambling SEO 
Unfortunately not going to give you all my secrets on here but I'll give you a few pointers (I'm nice that way).
Get more social. Brand signals and getting people to talk about you is a moderate indicator that you're not completely rogue.
Off the back of that I'd make some more, non-promo led content. Looking at your site (y mi español no es muy buena) all your content seems to be promo driven. Get some content up people want to share and link to.
As an affiliate, you really need to offer 'more' to your user base. Give them tools to track their play or have exclusive offers or set up something like a shop they can earn points for based on their play. Ultimately there are 1000 affiliate sites they could use why are they going to recommend yours (and by recommend I mean talk about and link to).
Gambling SEO requires a creativity based almost entirely on what you can do to get people talking as (as you've discovered) people consider all links you try and acquire or share yourself as spam. You need people's friends or other people they trust (influencers) to be talking about your site.