@Ratbag: In order to help you, we need more info. I assume you want to stop a user to send you./text/msges isn't? From my knowledge-Telus can't legit do that, but you can install a (Ph/Text blocker App). Here's some for Android users. 1) SMS Blocker. 2) Mr.Number +more in Goggle store. If you've an iPhone wait for a reply about.
Keep in mind that -Telecom wireless it has to comply, with internal policy rules. Having said that, don't expect -Telus will solve all the issues. Blocking Phone#s +Texts/brings some side effects, so do it at your own risk. <ReadMe-soon> "v9"
With Android there should be settings to create a blacklist of texts and phone numbers you don't want to see.
They basically go to your spam/ignore folder and you set the ring-tone for them to silent. You still receive them, but you ignore them.
1. Open Messaging app
2. Tap the 3dot icon and go to the Settings.
3. Scroll down, open the "Spam Filter" option and make sure it is enabled
4. Tap the "Add to spam numbers" options, tap the Add icon and starting adding Phone Numbers or Contacts to your spam list
5. You can also use the Match Criteria option and send the messages sent from a phone number starts with specific digits, right to the spam box