A son wanted to buy a camera, but his mother told him that they don't have enough money and then turned his attention to the gas bill. Here I understand that she wanted to drop him a hint that she has to pay the bills, so there is no money to buy a camera.
Mother: Have you seen this?
Son: No. What is it?
Mother: The gas bill. It arrived this morning. And we haven't paid the phone bill yet.
Sentence in bold is present perfect. I was explaining to my student that this sentence points to the thought that we have to pay the bill, so this sentence is not aimed at expressing the result we have not have now, but it points to the obligation we need to do. This way it is present perfect, but was not used purely for it's "natural" purpose.
What do you think?