That's actually what government is for. You pay it money, and if you have a good government it includes a branch to make sure consumers aren't ripped off/poisoned/injured/killed/etc.
Some governments, like the EU, are actually quite good at this.
A commercial consumer group can always be bought out, infiltrated, or threatened with bankruptcy by someone with superior spending power.
A government can only be taken over from the inside - often by those who pretend to support libertarian ideals, but in practice simply want to operate at various levels of criminality without challenge or oversight.
But a government can never be taken over completely. There are always people who believe that market forces are a naive and unworkable ideology, and are willing to work against their excesses. They have a natural role in government regulation, but no natural role in markets.