Should I consider my conference paper as published, if fee is paid but I didn't attend the conference? I submitted a conference paper some time ago to a trusted highly ranked conference. Strangely enough there's almost no communication from their part, no replies most of the time to my inquiries.

The paper got peer-reviewed and accepted, I paid the fee (around 500usd), I asked just a week before the conference if it's necessary to attend it because it was difficult to book a ticket given that I had only one month left in my old passport and I didn't have the new one, I provided a proof of that (scan of my old passport), but I got no reply and considered this as "ok" since this is what I wanted.

Now I am running out of time to graduate my PhD and I need to know whether it's considered published or I can submit it somewhere else. Should I bring something stronger in my email to catch their attention like "legal fight, submit somewhere else,etc" or just wait longer (presentation was exactly 10 days ago)?
what I am missing in all of this?

conference link if that helps
If the proceedings have been published and your paper is included (and usually at this time it is included), your paper is published.

Check the proceedings.

Is this kind of link of the conference that you need: index of proceedings

I think it will be published later. At this point if nobody presented your paper at the conference, it has to be considered public after inclusion in the proceedings only, so you need to have evidence of such proceedings publication.