"the government should step in" and "free market" don't go together, fyi...
Take an economics class. "Free market" is the name for a type of market structure, as compared to things like "oligopolistic competition", "monopolistic competition", and "monopoly". "Free market" does not mean 'companies do whatever they want', thats not even the type of phenomena that it is describing.
The cellular service market is not free market competition, it is oligopolistic competition. Oligopolistic competition is typified be domination by a few large companies (AT&T and Verizon have 70% market share, add Sprint and T-Mobile and you are at 95% of market share), where there are very high marketing and branding expenses and higher margins.
Free market competition is typified by many firms, competing in offering a relatively commoditized product with with lower marketing expenditures and lower profit margins.
This is a case where the government could step in and enact measures to commoditize the cellular service market and make other changes that would move the market towards free market competition and better price and service for consumers versus the current oligopolistic market where massive market-dominating corporations abuse their market power to keep prices high.