How to open the letter of Unicom unlimited traffic?

Unicom Tencent wangka users can log in to China Unicom mobile phone business hall APP > when their traffic usage reaches 40G in the current month. Service > query > my basic information > lift the traffic limit, and handle the lifting of the 40G traffic limit. After successful processing, there will be SMS notification;

Edit the short message "KTBXLL" and send it to 100 10 to cancel the 40G traffic capping. After the processing is successful, there will be a short message notification.