Even if is outsourced, they must put a description in the payment. Is required. You just have to provide them that number assigned to your account and that's it. That number is for Bitwage to be able to identify the payment assigned to your account. Imagine they have hundreds of payments... Insist if is necessary.

Once, myself I forgot to put the details for a payment and then I contacted Bitwage support and they were very friendly and helpful. Next day I had my BTC sent.