I doubt Coinbase would purposely ignore your transfer. It's more likely that Coinbase's banking partner either hasn't received the transaction itself, or that it is received, but not yet fully cleared. The slow communication between you and Coinbase might be the result of them simply not having any information about this case to share yet.
I would give it a few more days to see if everything comes through well. Wait until wednesday or thursday to see if anything has changed, if not, contact them again.
I would have thought 21 days would have been enough!!