In need of utility service

My plan covers 1100 Mbps of WiFi, and for the past few months I have been getting 5 Mbps, making my service unusable - I have been living off my phone hotspot. Originally we thought it was the router, so we upgraded it to a new Xfinity one. That didn’t work, so a technician came to check out the problem — he concluded that the problem may lie with the coaxial cable that crosses the roof: the cable is old and exposed to the elements, and the only way to access it would be with a bucket truck, as the property is a tall townhouse with no roof access. He said he would set up another appointment and include this in the notes. The next technician that comes by also does not have the necessary truck. He checks out the setup and speaks with his manager about scheduling the truck, which he also deems necessary. Tells us they will be arriving the next day — nobody shows up. I call Xfinity to speak with an agent, we troubleshoot for an hour before he also proceeds to make an appointment for an in-house technician with the bucket truck. I confirm numerous times with him that this next appointment will have the right truck to reach the roof. When the technician arrives a few days later, he does not have any way to access the roof cables, and comes to the same conclusion: we need the truck. I speak to two other agents later that day, who both promise me there is an in-house technician with the proper bucket truck on the way. Nobody shows up. This has now become 3 separate technicians and three separate agents all telling me they are setting me up an appointment with the proper equipment, and each time the problem gets passed on. I am at quite a loss of what to do from here — who to contact and how to resolve my issue.