How to reverse to old version of Tonic, of fix the changes theme made?

A week ago I’ve noticed that my sites that are created in Tonic got completely screwed.
Now front page doesn’t show static page as it’s set, but some random excerpt from the page with button “read more”. In addition to the fact that I don’t need it, “red more” doesn’t lead anywhere, but reloads the same page, so I cannot open full page.

How do I fix it?

See https://executive-coach.net.