What happens when you try to send messages?
Do you receive ANYTHING when someone sends one to you?
Is 3G data blocked on your phone or on your account? Picture messaging doesn't work over wifi.
Did you get your phone from koodo?
Does regular text messaging work okay?
Which phone do you have?
You must have a data block on your phone - this block was probably requested by you or the account owner. You can call customer service or use self-serve to remove data block (just becareful of 'background data' causing you to pay overage charges).