What's wrong with the chairman of the company not answering his phone?

If that's the case, my analysis is the first case. He may be presiding over a meeting, so it's not convenient to answer the phone and reply to the text message.

The second situation is that he may be in contact with very important business and cannot interrupt their negotiation.

The third situation may be that the information is not good and you can't receive your call.

The fourth situation is that the mobile phone is not around, and you don't find the phone and text messages you sent.