Xfiniti techs split my line with neighbor. Streaming doesn't work in evenings when everyone is home

New neighbor moved in next door.  I saw the line crew dig up the same pot that runs to my house shortly after they did.  Now we can't stream anything even though we're paying for high speed in the evening.  Get pauses, low quality video, audio drops and connection resets from Netflix and Prime.  99.9% sure the techs split my line.  Neighbors are friends but their kids are heavy online gamers and they play all night every night. 

 Xfiniti doesn't allow you any mechanism to actually describe the problem to anyone who can understand the technical issue involved.  Front line techs just want to reboot the modem and run speed tests during business hours when no one is home and, of course, the problem is not in evidence then (smh). 

Don't know what to do here to:
A: Reach someone directly who can actually do something. 
B: Demonstrate a problem to them that only occurs during off hours when the support center is closed.