How can I maintain kinship ties with relatives who have initiated hostility and severed kinship ties through their actions and abusive words, and would my failure to communicate with them be considered a sin?

The matter of kinship ties is grave, and Allah has commanded their maintenance and warned against their severance. Maintaining them is obligatory, and severing them is forbidden and a major sin. If relatives initiate hostility and severance, the sin is upon them. If one can bear with them patiently and maintain ties with them despite their severance, that is a great good; for the Prophet, peace and blessings be upon him, said: "The one who maintains ties is not the one who reciprocates, but the one who maintains ties is he who, when his relatives cut him off, he maintains ties with them." If their harm cannot be endured, then maintain ties with them through available means that ward off their harm, as maintaining ties is subject to custom.