Son neglects salaah and quraan and doesn?t talk to family

salaams muftisaab.hope you are in the best of health.alhumdulillah for your excellent work.i desperately need answers to some questions.
1)I HAVE A SON FOR WHOSE EDUCATION I HAVE PAID.DURING HIS STUDY YEARS I ALWAYS INSISTED ON HIS SALAAH AND QURAAN ALWAYS NEGLECTFUL BUT I KEPT ON HARPING ON IT.HE GETS ANNOYED WITH ME.I HAVE ALSO GIVEN A VEHICLE FOR HIM TO GO TO WORK.NOW HE DOES NOT EVEN SPEAK TO ME(FATHER).HE HAS AN ISSUE WITH OTHER FAMILY MEMBERS ALSO.THE LAST TIME I TOLD HIM THAT HE MUST DO WHAT IS BEST FOR HIM.WHEN I TELL HIM ANYTHING GOOD HE ALSO HAS AN ANSWER TO JUSTIFY THAT HE IS RIGHT.HE ONLY PHONES HIS UNCLE(MY BROTHER)WHEN HE ENCOUNTERS A PROBLEM WITH THE CAR.MY SON DOES NOT EVEN MAKE SALAAM TO ME ANYMORE.PLEASE ADVISE.