I'm Bronze I, my last game I had all silvers on my team, and all silvers on the enemy team... This doesn't seem logical if I'm not in my promos. My alternate account is Silver I, getting ranked against gold people. Why is this a thing... 
It all depends on your MMR. Your MMR is the real matchmaking system. Your Rank and LP don't influence who you get matched with. The more games you consecutively win, the higher your MMR will be. The higher your MMR is, the higher the rank of the players in the game will be.
Also, since you are in bronze/silver 1, you will be playing against the next elo. Your MMR WILL be high enough to play with people from the next elo. Just remember, just because they are one rank above you does not necessarily mean they are better than you.
You should see it as a good thing. You probably have a very good MMR, meaning you are technically at the same level as them.
Take me for example, I'm plat 5 but I play with low Gold and even Silver sometimes because of how garbage my mmr is. THAT sucks.
What's even worse is level 20 players getting matched with golds and platinums. They can't expect to learn when they can't even get an attack in without getting insta killed. This problem also exists with fresh level 30s getting automatically matched against golds+ in first ranked games..
