All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Behaving kindly with parents and keeping ties with kinship are of a great status in Islam. In fact, many verses in the Quran emphasize obedience to parents except when they order one to desobey Allah.
Indeed, Allah has put the right of parents right after His Right.
Allah Says (what means):
• {And your Lord has decreed that you worship none but Him. And that you be dutiful to your parents. …} [Quran 17: 23]
• {Worship Allah and associate nothing with Him, and to parents do good, and to relatives, orphans, the needy, the near neighbor, …} [Quran 4: 36]
• {And We have enjoined upon man goodness to parents. But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them…} [Quran 29: 8]
So, you should keep relations with your parents and be kind to them; your children must also do the same. This can be done through sending them presents, calling them often, … etc, until you think that you achieve this objective, which is being kind to your parents.
You should also call them to Islam in a gentle and wise manner. We hope Allah will guide them thanks to you and you will be rewarded for that.
We ask Allah to guide us all to the Right Path.
Allah Knows best.