I know relatively little about the topics of the dictatorship or the "dirty war", but even some extremely basic research, such as looking them up in Wikipedia (
https://en.wikipedia.org/wiki/Dirty_War), is enlightening, and, even better, supplies a source for the estimated 30,000 murdered or disappeared, from
https://nsarchive2.gwu.edu/NSAEBB/NSAEBB185/: "22,000 people murdered or disappeared by military between 1975 and 1978 according to secret Chilean intelligence report"...
"[T]hese lists include 'official' as well as 'non official' deaths. We got this from the Army Intelligence Battalion 601, located on Callao and Viamonte streets, which is under the Army Chief II of Intelligence at the Army general Command of the Chiefs of Staff of the Army. Those listed as NN are those unidentifiable corpses, almost 100% correspond to extremist individuals eliminated by "left hand," by the security forces. The tally of those killed and disappeared from 1975 up to date is 22,000. Luis Felipe Alemparte Diaz"
Given that democracy was restored in 1983, extrapolating the figure of 22,000 is reasonable, and that's where the figure of 30,000 comes from. It's not a made-up number, as our toddler-president and his cabal of dictatorship apologists imagine.
Trolling down's syndrome sufferers, singers, schoolteachers, and the like is one thing, trolling survivors and the families of the disappeared is a new low. There is simply no comparison between the terrorist attacks of the time, and the state-sponsored murder campaign.