Get it professionally repaired. Make sure you get it in writing that the damage was caused by Comcast.
I've asked a Comcast employee to help you. You should expect a reply in this thread.
Hi Wolf6 -- Thank you for bringing this to our attention. I can get a damage claim created for you. Please send me a PM with your name, full service address, and either phone number or account number. I'll be able to get a claim created with this information.
Click my name (ComcastZach) and click Private Message Me.