I have two koodo phone, me and my daughter. We can call each other and the calls go through, but when a non-koodo phone tries to call us, they get a busy signal. We can call out, and send/receive texts.
Have you checked if the landline has some restriction? I would try to restart your cell and use another phone to call and see if it come through. Normally, if you block a number, when that number call, it will go to voicemail or busy signals.
Are you new customers and ported numbers from somewhere to Koodo?
My wife and I are having the same issue. We can call from cell to cell and cell to land line, but not land line to cell. We get what sounds like a fast busy. We were able to call her mother from the land line, who is also on Koodo.