My bronze 3 promos

so recently I have decided to try and climb my way up the ranks. So i was in bronze three, dropped down to bronze 4, got back to promos with a free win, and took a quick 2 day break because exams. i came back and I'm out of my promos and down to 80 LP. What the hell happened, i thought you weren't able to drop down from promos? plz help me