Unappreciative Friends

So my husband and I have these "friends" who call us every time they seem to be in trouble. They expect us to drop everything for them and their kids. We have 3 children of our own and I have enough on plate to try to remember... I can't remember everything about their lives too! I don't mind helping out every now and then, but every time we ask for help either we don't get it or they call us telling us to come get our kids because they have an "emergency." This past week was one of those unappreciative weeks... I just got so annoyed!! I mean.... my kids are more important to me and my husband then theirs are... I love their kids dearly, but my family comes first. And the other day there was a huge blow out because I put my family first. I was trying to get my husband something to eat before he went to work... lost track of time... and got chewed out for it. It just really makes me mad when you go out of your way to help someone and when you try to do something for your own family they jump on your case. Not to mention they make a big deal when I get on to my kids... I have never heard them talk nice to their kids. They are always yelling and putting them down. We have a child who is a little hard headed and tries to push our buttons, but we love her and hug on her and kiss her, but we also have to be stern with her more then the other two. They yell at all their kids... their kids talk back, their kids are rude, their kids have problems. It really makes me question when they say they love kids so much if they really mean it, because they don't really show it. I wonder sometimes... if life would be a little more relaxing if we didn't have to deal with them on a daily basics?!