BochurBrains I had that problem too. I think it has something to do with an attachment that they send (which the phone doesn't seem to recognize).
Since you've signed up before you had your classic you won't receive texts.
What worked for me, was to set a Google voice number to forward to your phone, and then sign up to kol haolam with google voice. This should cause you to receive the attachment, and then it should work normally. You can then unlink/unsubscribe your Google voice number.
If it doesn't work, then at least you'll get the texts through Google voice.
Please respond with your experience.