Removal of aerial connection and placing it underground

Hi,

I have an aerial line that needs to be removed and placed into the existing underground vault so the utility pole can be removed. I've opened at least 3 support tickets with Xfinity customer support and they've all been closed without resolution. Can someone here help me with this? This is not an active account and after the line is placed underground there is no intention at this time to begin service. So there is no way to sign in to get service. Please advise on a path forward here.