Why does the website say that things are available in the store and won't let me order these items online but when my husband goes into the store to get these items they are not there and he is told that they don't carry these items.

My first suggestion is to make sure you've selected the right Dollar General store location online when checking availability. If you've done that (great!), then the unfortunate truth is that most stores with both physical and online stores struggle to keep their inventory of items and the quantities in sync between online and physical store. Some are better than others at this. On the technical side, I don't know why this is even an issue these days, but in practical experience, it's still the way of things.

I made sure that it was Pawnee store... My husband has gotten told that they do not carry the items...but their website says they do