I am having a issue trying to see my nieces. My sister doesn't have custody of her kids and moved away. But the people raising her kids only have gardionship of them and won't let me see them very often. In fact, it has been since December since I have been able to see them. Every time I call they are either going out of town, one of the girls are sick, or they just won't answer the phone.

The people raising them have no relation to one of them and the other child is in question of them being related to them.

Do I have any rights to visitation that would stand up in court?

Sorry, I don't know of any cases where a aunt has gotten any visitation right.

You are on shaky ground. Why do these people have guardian ship if they are not relatives?
The tried and true advice is to see a lawyer, but I don't know the circumstances... you may have a chance.