They may have originally been created to protect consumers, but they've been manipulated and lobbied for so long that they now exist to protect entrenched business interests.

Repeating the argument does not make it more correct. If you're trying to contradict the idea that government regulations are not a large barrier to entry you might show some evidence, preferably in the form of a peer-reviewed study. Your study should also compare the externalized costs of not having said regulations. Even better would be to admit that you've been drawn into a ridiculous position and exit the conversation with as much grace as you can muster.

"contradict...not...barrier" is a triple negative, too much work for me.

Samuel Johnson springs to mind, but if you'd like, substitute "contradict the argument of my previous post". I would prefer that phrasing, but I've often been disappointed at the tendency of people to take issue with small ambiguities or details at the expense of the actual argument.