How to ESCALATE MDU process to the right department?

My internet has been slow for about three months. It’s supposed to have a download speed of 500 Mbps, but I’m consistently getting 20-30 Mbps, and sometimes even less than 1 Mbps. Comcast has sent several technicians to inspect my home, and each one has identified the issue as a problem with the cable between the Comcast lockbox and my house. Despite their assurances and promises to open repair tickets, nothing has been fixed.

The fourth technician came on August 17th, and I requested a screenshot of the ticket he opened. The screenshot indicated an "MDU process request." On August 29th, a fifth technician was sent to address the MDU process supposedly. Unfortunately, he focused on checking everything inside my home even though I told him that the issue was with the outside line. He informed me finally that the problem was external and that he would open another MDU process ticket. I followed up on August 30th and was told a MDU technician would arrive between 8 AM and 8 PM that day. I waited the entire day, but no one showed up.

At this point, I need to escalate the issue to ensure the appropriate technician is dispatched for the MDU process. It seems that call representatives are unable to resolve the problem, as they keep promising that the right technician will be sent, yet nothing changes.