Although this is very painful for you now, your parents shunning you will end sooner rather than later. They're in their late 70's and will need help when their health begins failing, and likely no one in the congregation, including your relatives will lift a finger to help.
My mom has shunned me for 30+ years and is now dying from cancer. And she has sent word to both my brother and me that she would like to see us to choose what we want from her possessions. This is really strange, because she was never a wealthy woman. Neither one of us has directly responded to her. I'm not physically able to travel the three hours it would take to see her. My brother, on the other hand, recently traveled there to see our non-jw aunt and didn't bother to drive the three miles from her house to our mother's home.
I suspect her motive in seeking us out is to assist in her care, but I'm not certain. From what I understand, there are jw relatives somewhat helping her out, but most of them are elderly and have health problems of their own.