refund for 4 weeks with no service

I had no Xfinity service for 4 weeks because of a broken cable to my house.  I requested a refund of one month ($255) and was offered only $90.  That was unacceptable, so the agent said she would escalate it to another office.  After not hearing anything for 3 weeks I called again and the new agent said that the $90 was all I could get after nearly an hour on the phone 30 minutes of which I was on hold while she investigated.  I was told the only appeal I had left was to use this forum.  She would give me no other contact numbers in Xfinity.  

Please note that I reached out to Xfinity on four separate occasions to request a technician visit.   Each time I pointed out the end of a large coax cable sticking out of the ground about 2 feet from the Xfinity post.  I was told that could not be my line.  In fact it actually was and there was a corresponding stub sticking out about another foot away.  The fourth technician acknowledged that was the problem and called another who had the proper equipment to splice the cable.  That technician took less than an hour to fix it and bury it.  

If you examine the record of my calls my case was closed multiple times without any action to restore my service.

So my question is how can I get the refund I deserve for no service for 4 weeks?