Am I supposed to get a permanent ban only after 1 warning??

I had 2 games of toxicity. I didn't really think much of it since the other players were also being toxic. That doesn't matter in my permanent ban though, what I'm really concerned about is why I got a permanent ban after 1 ban prior. I read some other posts and apparently you're supposed to get 3 warnings before a perm ban. What I said I didn't really see as offensive, no where close up to the scale of "kys" or anything related to that whatsoever. Please help