Comcast 2 weeks overdue to terminate service

We have a cancel service order with Comcast that was supposed to be effective January 12, 2018. On January 16, with services still running, I called to ask "what's up" and I was told it would not occur until the 19th, but the final bill would only hold us accountable through the agreed termination date of the 12th. On the 22nd, with service still running, I called again and I was told it would take "a few more days" to cancel service. As of today, January 25, it is still running.

What this means is, the phone numbers that are supposed to be ported to the new carrier, cannot be ported. So we have new phone service that we've been paying for since 12 January, that cannot be started.

We are a (duly registered) nonprofit religous organization, and we do not have the financial resources to pay two carriers, nor the volunteer time to keep imploring Comcast to let us go.