Unregulated markets produce good outcomes under certain assumptions. If a company can offer you one price but then raise the price later because there are high costs to switching to a competitor, then an unregulated market does not produce what's best for society.

Telling a business what price they can set probably isn't going to create a good outcome, but there should be some kind of consumer protection law or regulations that help customers be informed before they sign a contract with high switching costs.