Men are not the biggest fans to communicate by SMS. Better he will tell you everything personally, than he will spend time on typing a message, especially during the working day. But some of his messages may eloquently say that you are not as dear to him as you would like.
“I didn't promise you anything.”
If you start to reproach him for not even bothering to answer you, he replies that he did not promise anything to you, and he owed nothing to anyone. It hardly makes sense to catch something with this man.
"Sorry, we can not see today, other plans"
He already had plans to meet you. It's one thing if something really urgent happens. But if he simply chose to do something else, it means that you are not so expensive to him.
“I'll call you later”
And the call did not follow. If he wanted to talk to you, he would certainly call back. If he has not fulfilled the promise, consider carefully whether you should contact such a person.
“Why do you write, you know that I am at work”
This is especially offensive if you really have something important. He made you understand that he does not want to communicate with you, and dating is enough for him.
You sent him a message that you love him or you miss him, and he answered you “aha”? This suggests that you are most likely indifferent to him, otherwise he would have expressed more definitely.
If he does not respond to your messages, this is the first sign indicating that he does not care. It doesn’t matter what happens to you and for what reason you write, he will not even consider answering. Of course, we are not talking about situations when you wrote to him and he is silent for 10 minutes - he is probably really busy.