Is the questioner sinful for not visiting his mother, who refuses his visits and lives in another province, knowing that he talks to her daily and she is pleased with him, but he fears disobeying parents and severing ties of kinship?

As long as you are trying to visit your mother and she is preventing you, there is no sin upon you. You must continue to maintain ties with her through calls and similar means, and visit her if possible, for honoring one's mother is among the greatest acts of obedience.