Regain control on his activities: 

It is the simplest method to regain control. Your children have an addiction to the TV or a smartphone? Guess what? Both of these work only when YOU recharge them. Thanks to Direct-To-Home set-top box services, TV is rendered useless unless you get a top-up. And the extra conversations on your kids’ phone is possible only because you choose to pay their phone bills. Refuse to do so in extreme cases. In other circumstances, learn to change their  plans such that they get limited access to 4G network and free calls.
WiFi:
The grim reality of the far-reaching effects of going digital stems from the same root – A WiFi connection. Even though you have stopped recharging your child’s phone/T.V. as per their convenience, the WiFi connection seems to duck this new decorum rather easily. Along with the above, try and pose restrictions on your WiFi connection. In case you’re currently operating on say a 3 Mbps speed, turn it down to a 1 Mbps. Take the assistance of your Internet Service Provider if need be to figure out a plan that will suit your requirements.
Parental Controls:
Every television thankfully has the facility of providing parental controls. Use these services to decrease the exposure-bandwidth on your children. The same applies to online streaming services like Netflix and Amazon Prime. Create different profiles for you and your kids, thus enabling restricted access.
Firewall:
It is a widely used service in big corporate houses but the same can be incorporated in your home network. Again take the help of an expert. There are many good local IT companies who provide these services, thus it is not something which will be too expensive or difficult to find.
Give More Time:
No matter how many restrictions you will want to pose, you cannot blame your children for having been given the facilities of technology in this era. Instead what you can do is to spend more time with them. Show them the means of entertainment you were exposed to while growing up yourself. Take them out on picnics and facilitate the importance of going outdoors. Relive your childhood while you grow old with your children.
Enroll Them For Extra-Curricular Activities:
Your kid is succumbing to his/her phone/TV simply because they probably have a little extra time on their hands. Hence, enroll them for extra-curricular activities, either in school or other clubs, and help them build new hobbies aside from academics. However keep no restriction of choice here. Let them pursue whatever it is that their heart desires – right from tennis or cricket to drama club or elocution. This not only takes up their free time but also helps in inculcating better interpersonal skills in them.
Make Smarter Choices:
Just when your child is stubbornly asking you to buy him/her the new iPhone, make smarter choices instead. For example, instead of an iPhone, buy him/her a Kindle. Not only is it a LOT cheaper but it also helps in building a frequent reading habit in your child while also increasing his/her vocabulary. Similarly, there are better alternatives to all kinds of technological products that your kids want you to buy for them.
Set Some Ground Rules:
Over and above the aforesaid, make sure there are certain no-tech ground rules in the house. For example, no phones or digital devices while eating, or no tech during a family weekend, or no social media exposure till a certain age. Suit yourself but more importantly lead by example!
Get him to attend MIND TRANSFORMATION WORKSHOP : 
If nothing of the above works or seems difficult, have your children attend my ‘MIND TRANSFORMATION WORKSHOP", hundreds of participants break their years-long addictions to Smoking, Drinking, TV or Mobile FOR EVER.

WE HAVE WEEKLY FREE SESSIONS FOR PARENTS AND STUDENTS IN MUMBAI. TO ATTEND THOSE SESSIONS, FEEL FREE TO CALL 9594593656 AND BOOK YOUR SEATS.