Blocking a friend; can they text you?
Hi Dinah. Here's what I found from Koodo Mobile's website:
You can use one-time Call Blocking by dialing #31# (67 for landlines), plus the area code and number of the person you’re calling, followed by pressing either the Send or Talk key. One-time Call Blocking varies according to a person’s wireline or wireless network and therefore cannot be guaranteed. Double-check instructions with the landline provider if you're calling a wire line phone or a non-Koodo phone. (source)
If you want to permanently block someone, you will have to contact Koodo Mobile.