The thing is a lot of people don't realise is that THEY have the power. Simply boycott such companies.
If companies are viewed as bad people stop going to them. Tesco is a good example, they had scandal after scandal using workfare free labour, tainted food, bribery and tax evasion but seemed untouchable to the extent they could do whatever they wanted and had the government in their pocket. They always got planning permission and nobody ever investigated them.
This happened from 2001-2011 then people got tired of them and a small number of consumers went elsewhere pushing most of their stores into unprofitably. As a result they fired more staff and whipped them harder which made even more people hate them. People went elsewhere and they are in serious trouble now.
For instance I don't like ZHC (at will in the US) so I don't patronise any companies or organisations that use this sort of labour. I also don't like Ford cars as I bought a brand new one and it fell apart before my eyes. They will never get a penny off me again. Or shitty tactics like turbo tax thing. Never get any money again from me.
But you complain.... yet still buy again from them are they going to take your complaints seriously? Unless of course there is a total monopoly on a product.