Divorce Support Forums: Non Custodial Parent Rights

I have been divorced since 1999, i still have a 13 yr old son living with his mother. Since the divorce she has moved 13 times, each time hiding and not allowing me to see my son, i have seen him several times in the last 7 yrs, in march of 2005 i found them and provided a place for them to live, all i asked was for her to pay rent of 250.00 per month, just as she would have anywhere else. That lasted about 4 months, then she moved. She didn't notify me when she moved so of course i got stuck with all the household utility bills. i paid them, and then began the search for my son, i found him in Racine, Oh, within days of contact she moved him again, this time to Louisville, ky. it took a while but i finally found him, upon contact she moved him back to Racine, Oh. upon contact she moved him to NC, then KY again, i have found her again in Wayne county Wv and have had contact with my son. I want to see my son, he is 13 and i am being told by her neighbors that he lives in very unsanitary conditions, the fridge full of beer instead of food, not going to school regularly. I don't know what to do, can anyone help