First, read the English article below.

If you want to cut off contact with someone you don't wish to be around, you may want to consider blocking that individual from calling or texting you. This may not be necessary if you don't have any regular contact with the individual, but it certainly won't hurt.  To block calls on an iPhone, select that individual from your contacts list and choose "Block This Caller." To block texts, go into your messages, choose the individual you want to block, and select "Details," then "Info," and then "Block Contact."  To block calls/texts on an Android phone, go to Call Settings and select "Call Rejection," which will take you to the "Auto Reject List." From there you'll just search for and select the number you wish to block. To block calls/texts on a Windows phone, go to Settings and select "Call + SMS Filter," then switch the "Block Calls" function on. Then just hold down the number you want to block, select "Block Number," and hit "OK." If you use a BlackBerry phone, you'll need to speak to someone from your wireless carrier to block an unwanted phone number from contacting you. Even if you manage to avoid someone in person, that individual may still be able to contact you via social media. If you're friends with or follow someone on a social media site, that person can find out what you're doing or where you're going, and he/she could send you threatening or harassing messages through social media as well.  If you're friends/followers with the individual on social media, you can unfriend or unfollow that person. You can also block that individual so that he/she cannot see what you post and cannot contact you in any way. If you're not friends/followers with the individual on social media, or if you've already unfriended that person, change your privacy settings within that social media site so that only your friends can see what you post. If the person you're trying to avoid has your email address, you may fear getting an aggressive or confrontational email from that person. You can prevent this by blocking that... 

Now, please write a short abstract for it in Vietnamese. Abstract:
Chặn số liên lạc với người mà bạn không thích. Cắt đứt mối liên hệ trên các trang mạng xã hội. Ngăn chặn người khác gửi thư điện tử cho bạn.