First of all, it is necessary to find out why the customer does not pay back the money or reply to the message. If it is best to find out the reason, we can at least know a specific situation, whether we want to default for free, or whether there are really some situations that make it impossible to pay back the money now and we are embarrassed to reply to the news, or whether we deliberately default, which needs reminding.
In short, it is best to understand a situation and then come up with different solutions according to this situation. After all, different things are treated in different ways. If it's the first kind, that is, the kind that wants to deadbeat for free, then I don't think we need to respect people who don't respect the fruits of your labor.
This is that you don't take your loneliness seriously and want to take advantage of it. In the face of this, we can definitely shield him and shield him directly. In any case, he can't really blame this account. You must get it, and you can't take advantage of him for nothing, so an eye for an eye, a tooth for a tooth, and don't take his project again.
If there are some special circumstances in the second case, so he doesn't pay back the money in time or answer the message, then I think he should make it clear first, whether it is true or not, and then judge what to do. After all, it is not easy for everyone to do things.
Therefore, we should understand each other on a reasonable basis, so I believe that he also knows our good intentions and will definitely reply in time and repay something.
In a word, this problem is mutual, and we should see how to do it according to the specific situation.