Charged for disconnected services, where to return equipment?

Hello,

I keep running into dead ends while trying to resolve why we get billed for services at a location we haven't been at for 5 months. In June our small business moved across town and internet was transferred to our new location. Although we moved service has continued to be billed to our company credit card. It's now over $1000 in charges for a location we haven't been at for 5 months yet we pay our new bill on time monthly. 

I contacted the sales rep as it was the only live person I had contact information for. She told me to bring our old equipment to the service center. When I attempted to this the service rep said they didn't have anything to do with Comcast Business and only support Xfinity customers. I can find ZERO information online about where to return Comcast Business equipment.

PLEASE HELP. We are a small home based business and these excessive ongoing charges are killing us.