Right, I'm not sure how the promotion of 3rd Spanish tier works, but I'm 99% sure I wasn't supposed to get promoted...I finished 3rd in regular season, which sent me to Promotion stage. However, I only scored one point from 9 games, I fell to last 6th place in the table, but after the penultimate match I got message I got promoted.
It's definitely not because of the B teams, since there are 3 regular teams in front of me. Plus I checked Promotion stage in different groups and it seems, that in every group the last team got promoted?
I can provide more information when