I need help with my girlfriend? Please!?

We were planning to go hang out when I drove up to see her and her guardians were ok with it at first but all of a sudden they wanted us to stop talking and not to see each other. They wont even let me call and explain every little thing of what we will be doing and going since we were gonna stay with my grandparents and be supervised. We are trying to settle this diplomatically but they are being overly stubborn about it. They wont even talk to me and then say no. She wants to run away with me or me take her with me. We live in kansas so what should I do. Kansas has strict laws on this and I would get arrested if I harbor her. What should I do? Also these guardians cause her major abuse and pain but they lie and havent ever gotten in trouble. I dont know what to do please help!