I honestly don't think this is true. I can definitely understand the feeling of "I'm stuck in ELO hell because I keep getting paired with feeders and trolls that cost us the game", and I've been of that opinion as well.
But the thing is, ranking up is not about getting lucky with matches. It's about plugging away hundreds and hundreds of matches and finding your average. I felt like I was "stuck" in bronze, and it was obvious to me at least that I was much better than most of the players I was getting paired with/against (whether or not it was actually true). I didn't break out of Bronze until I made a serious effort to play many matches per day - if you have a win rate of 55% or so, that's actually REALLY good. But it's still only 10% more that you are winning than losing, so it will take a while, and a lot of setbacks, and a lot of frustration to eventually raise your ranking. If you get discouraged at any point, you will never make it out of Bronze.
Another thing to consider is that it's smart to play to your ELO. Certain tactics and strategies that would never work in Gold can carry you all the way through Bronze. Look up guides and builds for your mains, don't just copy what the pros do but really LEARN from them, not just what to do but also how and why you should do it. Play champs of all roles when practicing, if only to get a better feel of how enemy champs will act/react. Work on your mechanics (last hitting, using attack-move properly, leading your skillshots, using the ` key in teamfights, etc). You really have to pay attention to every facet of the game in order to improve at all. Find 2 or 3 champs that you LOVE playing, and would not mind playing thousands of matches with, and just get so good with them that you can always win your lane/carry the team, regardless of how your team is doing. This will still only result in a 55% or so win rate, but it's the best way I've found to climb (just spamming queue with your main).
I would strongly recommend taking a long, serious look at your key bindings, going into practice mode, and re-bind them into something that suits your playstyle, or what your fingers are comfortable with. The default bindings are not very good and require you to take your fingers off of QWER a lot to get many functions done. A simple settings change can DRAMATICALLY improve your gameplay.
