slow internet - poor service

For over a week my internet speed has been around 300mbps.  While I realize there might be some signal loss, I am paying for 2000mpbs.  I called customer service and explained the issue, that nothing had changed inside my house and that it was an external issue.  I was told that there were 2 separate incidents where they were working on the lines locally.  First time a technician came to house, it was a contractor.  They get paid per piece of work that they do, so he replaced splitters, wires, ran tests, etc..., he was here for 5 hours.  He was unable to resolve the issue.  I called back to let them know that the issue persisted.  I was assured that an xfinity technician would be sent to the house.  Second time it was a contractor from another company.  He examined everything inside my house and then replaced the underground line from my house to the tap.  Issue still persists.  I contacted a xfinity again and asked for the issue to be escalated.  A "supervisor" informed me that the issue was most likely an issue with the signal being sent to the cable modem being out of sync, and that they would send an xfinity technician to look at the street side to resolve the issue.  My appointment was for 10-12, which then was moved to 5-7 pm.  I was pleasantly surprised when the doorbell rang at a little past 3pm, but quickly disappointed when I opened the door to find the contactor that was at my house the first time. I explained that he was unable to fix the issue and that the issue should have been escalated, according to the "supervisor".  He had informed me the first time he was here that he was unable to open the pedestal.