Legal Question in Business Law in California

Your question is too generalized to provide a useful answer. In general, probably not. As with most legal scenarios, however, there may be exceptions. I can envision certain situations where you might be able to require enforcement against Company C, but those would involve either (a) a contract where you could claim to be a "third party beneficiary" of the contract so that a non-party would have an enforcement right or (b) unfair competition. An answer regarding your specific situation would require a review of the contract involved and/or more specific information about the fact scenario.