What do I do about feeders?

So I've been in a lot of games recently where either our mid or our bot fed so hard that it was physically impossible to win a teamfight because their adc or their mage was getting back-to-back multi kills. It's really annoying because it feels like no matter what I do, my ranked standing is in the hands of teams that are giving out free wins by feeding. For example, I went 18/7 with Vayne the other day but our mid fed the opponent Leblanc so hard that I was almost always melted in a matter of seconds. Most of my kills came from picking people off out of position or ulting and out-maneuvering the opponent adc. Last game, I went Yasuo and I absolutely demolished the other Yasuo (it was a mirror match). I ended the game 4/1 and he ended the game 0/3. Our bot didn't get a single kill, didn't call an mia so i got ganked by their Lucian, their Leblanc, and their Warwick. Their Lucian ended either 9/1 or 8/1. This has happened in Ranked, Hexa, and normals. What do I do? What do you do when your team has fed so hard that you just can't win? It's really frustrating because I feel super helpless when everyone else has 9 or 10 deaths and I'm the only one with a decent or neutral KDR.