How do YOU deal with people who only contact you if they want something?

My husband has been trying to distance himself from his dysfunctional family but they WON'T leave us alone. The latest....he has been asked to do a bunch of home repairs for them at his expense. We happened to run into them while shopping and this was the FIRST thing out of his mother's mouth. Keep in mind that he has a brother in his late 20's who LIVES in that house and is PERFECTLY capable of fixing something and has plenty of time since he can't hold a job (the rare times he does have a job he just calls in sick until he gets fired), and their landlord won't be responsible for repairs because they trash the place and won't keep up with the rent. When we say "no" we are bombarded with phone calls and visits from upset relatives because we won't share our "good fortune" with them. My husband came from nothing and works like a madman to give myself and our children a good life....is it horrible of us not to want to help them just because they are blood relatives?