Hi 3kids, yes, I tried being the nice doormat too. It didn't work for me, but maybe it'll work for you. Just kidding, it doesn't work for anyone.
If she is in an A, then she has chosen her path. Didn't Sandi tell you W is having all of her needs being met by two men? Why should she change?
My 2 cents, stop answering the phone. Force her to text you, if that's easier for you. But learn the most powerful word in the English Dictionary: "No", and leave it at that.