Can someone explain Promotional series to me please?

I just don't understand the Promo series from Silver 1 to Gold 5. I have lost my promos 6 times now, usually by losing all 3 first games. As soon as I fail my series I get right back in by winning 1 (sometimes 2) games right after. I gain 27 LP per win against Silver 1 and 2's and Gold 5's. As soon as I get into my Promo series to advance to gold 5 though I find myself playing against Gold 1 and 2's and Plat 5's.

I understand that Divisions and ELO are different and everything, but the skill difference between my Promo series teammates and myself vs my Promo series adversaries is a very noticeable difference. Can someone please use REAL LOGIC (not Rito logic) to explain this to me, please?