If you send a message to a person, he often doesn't reply or answer the phone. Just to tell you that he is busy. Is it necessary to find him again?

No matter what the relationship is, just make two phone calls and send two text messages. If he sees it, he will always call you or reply to short messages. If he is interested, it can prove that he doesn't want to contact you. Sometimes you send a message without answering the phone, and he will read it. If you understand the content and ignore you, don't call again. The effect of pursuing will only be counterproductive.