Comcast WAN Routing Issue

We have a client that has 3 locations being serviced by Comcast.

All locations have static IP addresses.

The 2 locations have IP addresses that appear to sit on the same subnet, say 171.10.10.50 and 171.10.10.100 (not actual IP's)

The other location's IP address is totally different, say 75.140.x.x.

They have a web/application server at one of the locations having the 171.10.10.x static IP address.

Any external requests other than one originating from the 171.10.10.x IP address can get to and resolve the web server IP address.

Placed a call to Comcast Business Support and they sent a Signature support technician onsite who came to the same conclusion that i did, the two networks will not allow inbound traffic back and forth. We even tested trying the IP address of the location that has the web server; it failed to resolve.

The original ticket/call was placed on Thursday; onsite tech came out on Saturday. After the onsite visit which lasted close to an hour, he told me someone from Tier 2 or IP Provisioning would call within 4 hours. It's been over 48hours without a resolution and the client is not happy with this type of 'Business Class' service. Even the onsite tech they sent out agrees Comcast does not know what is going on. They keep opening trouble tickets to send a tech to check the signal, when clearly its not a signal issue; the router(s) are both online and users can get to the internet without a problem.

As it is, the client is contemplating jumping ship to a different provider.

Has anyone had any similar issues with Comcast before?