Unfortunately there is not a way to disable texting from only one number on the network. However, if you have a smartphone, there are several free apps you can download to filter numbers from contacting you. This apps require a data package to be used (or wifi connection) but can be really effective in blocking annoying communications.
Try searching for apps on your app store/google play/android market.
If you have a Samsung Android phone the feature is already present in alot of their devices (not all) To see if it is in your model go into your messaging app and click on the menu button on the phone and go into settings. Look right at the bottom for a feature to mark #s as spam.
If you want to block #s from calling you on the same device go into the dialer and do the same.