Any advice on climbing?

I've played 500+ ranked games this season so far but I'm getting no progress at all. I've been through Silver 5, 4, 3, 2, and 1. I'm currently back in Silver 3. Which is pretty much where I'm always at. I've climbed so far at times through win streaks but every time, I just get pulled back down by this matchmaking system putting me with low winrate players every time I'm doing good and having a win streak. This is just stupid and I've spent too much time and money on this game yet I'm getting nowhere. I need help, preferably from other players with the same or previously had the same experience I've had in this cancerous elo.