Can a company deny a request for a NON-O visa for a dependent spouse of foreign employees?

It’s likely the HR doesn’t know the process so will say no rather than help to find out. Good ones will help to at least give you contacts as many companies use agents for the visa process.

My advice is to speak with their Head Office HR. No company can deny you applying for your spouse in any case, but they are unlikely to pay for it unless it’s part of any employment offer. They need to only prepare supporting documents for you, then take them yourself to immigration.

The HR is not helpful.