Being Force to Pay more than I can afford

A consultant by the name of John is been harassing me since in the morning. He is busy calling me and I am telling him I can't make the payment he wants because am not working but he keeps saying insulting me and saying I must pay I asked him should I go and ***** because I honestly don't have the amount he is asking but I will pay what I can afford. He is very rude and by doing this to clients more people will not even pay a cent because of the tone of his rudeness and shouting