How does China Unicom cancel GPRS service by sending short messages?

Unicom's 2G GPRS traffic package was cancelled across provinces. Guangdong 2G users can send the following instructions to 100 10 to cancel the GPRS package for free: 1 You can send "QXGPRSD9" to cancel the 9 yuan package 100MB traffic superposition package; 2 send "QXGPRSD 15" to cancel the 15 yuan package 200MB traffic superposition package; 3 Sending "QXGPRS" can cancel all customized GPRS traffic packages, and this instruction can also cancel superimposed packages and free play packages. Users from other provinces can consult local customer service.