I disabled the "Promotions and hot deals" in the store notifications settings TWICE already.

It keeps getting enabled after a while and I find that GOG.com should respect their user's setting and choice to not receive spam.

If this keeps happening I'll just start marking all GOG emails as spam

Did you accept a giveaway, like the Postal 2 one? If so it'll re-enable them and you'll have to opt back out.

Yes, but the fact alone that this enabled the settings again without at least telling you in any obvious way is just disgusting practice imo.

And I mostly hear about those giveaways from friends on Discord, never though emails.

...

It does - it says it in pretty big writing next to the button

Indeed.
Still annoying, but definitely can't say they don't specify it. Even the button itself is in fact for agreeing to that condition, "and claim the game" being secondary.