One of the most popular theme was deleted

WP Porto was deleted

How I can download the lastest version what was here several days ago?

Only the author can tell you that, and it looks like you already asked them in the comments section of their other items.

There isn’t a way to download the latest version unless the theme comes back up or the author sends it to you. Note that just because an item disappears does not mean it was deleted; it could be temporarily taken down for various reasons.

I hope it come back.
But by the rule I can bought a theme in the morning and author can delete it in the evening and it ok.
Or in this cases will be refund?

If you’ve already downloaded the theme’s files and the author is still providing support during your active support period, then there is no cause for a refund, as I understand it.

See the refund policy here: