New Underground Cable - Not getting the same download speeds as used to.

So, a few weeks ago, my neighbor took it upon himself to dig a big hole in his front lawn to put cement down. Upon doing this, he damaged the underground cable that connected to my house. Comcast had a difficult time getting my neighbor to agree to install a new cable on his property. Comcast believed he did an illegal dig and was about to get some kind of permit but instead decided to install the new cable into the existing wiring I have on my property.

It's been two days and I've automatically noticed a difference in my connection. I'm on the 300/10 internet plan and use to get close to that, now I am only getting about 25-40 Mbps downloads throughout the day. I am pretty sure it has to do with my new underground cable.

My question is: Is there any kind of way I can get faster speeds like I use to without getting my neighbor involved with the underground connection on his property?