2B students bought an htc x3 10e Triumph. After installing the mobile phone card, they can't send short messages, and the number of the short message center can't be saved?

Maybe these SMS numbers have been changed. Just get the local SMS center number from the customer service 100 10 to which the number belongs, and then modify the center number in the SMS settings. However, there are also special circumstances. My name is HTC Rzeound. My center number has been checked, but it still shows "sending" when I send a text message, but I just can't send it. . . It may be a mobile phone problem, but also ask for a big answer! !