B.C.
CH - I have a 13 year old, 17 year old and 2 year old - all boys. I commend you for trying to teach accountability because that is a key value that will help him make good choices in the future. Some great advice I have been given: each child's consequences need to be different because some don't respond to grounding, yelling, talking, etc. the same. What is important to him? What can you take away that would really affect him? Even if it is his sports or activities... it is worth taking it away for a few weeks - a season - or a year, in order to show him true consequences in life. We have taken away guitar lessons from my older son, which was very hard for us to do since we want him to be successful with his music. But, it got to the point that he wasn't behaving as expected - we had to take drastic measures.
I hope this helps.... keep trying and you will see that it will be successful sometime in his future life!!