I imagine it's very complicated. Sometimes they just need cooperation on other things, then they own stock, their friends own stock, they run in the same social circles, you can bet many are just corrupt and if not their friends are, then there's the actual power the companies have (like the ability to build or layoff in their district, strategically hike prices, minor capital strikes, blackmail (remember who has all the data), all kinds of stuff.) Also, there aren't really any consequences to ignoring you anyway. On average, they'll either get re-elected because nobody notices/understands or they'll just be replaced by a new sock puppet.

This is why you'd want liquid democracy, arbitrary right of recall or something along those lines.