$100 Installation Charge for problem on Xfinity's End

Hello,

Recently I moved into an apartment complex which has existing cable lines and Xfinity service already setup. I had the self installation kit sent to me as I figured this would be no problem to set up as I have done it numerous times, not only with Comcast, but with other service providers without issues. 

Once I received the kit, I had everything hooked up properly, installed the app, but had no internet. The equipment had all of the correct light indicators as confirmed by the tech that I reached out to through support who went through all of their troubleshooting steps and came to the conclusion that the cause of the problem had to be outside of the apartment. They scheduled a technician and told me that due to the fact that this issue wasn't with the equipment or anything inside the apartment, I would not be getting charged for the visit. 

Once the tech arrived, he did confirm that the issue was outside of the scope of the apartment which was with one of the cable lines and I would again not be getting charged for the visit. 

As you can guess by now, upon viewing my upcoming bill I now see that I did in fact get a $100 charge on my bill after being told numerous times that the issue was out of my control, that my equipment was perfectly fine and is still what I'm using today, that I performed the self install without fail but that the issue required the technician's aid outside of the apartment and access to cables/panels that I did not have access to. 

Any help in having this issue resolved with my bill would be appreciated.

Thank you!