Dispute $100 Service Charge

I was charged for a $100 in home service visit due to poor signal quality coming to my property from Xfinity infrastructure. I have tried twice with the billing department to have the charged removed, and been denied both times because the technician marked the service as an "in-home visit" according to the billing department. The technician did not enter my home, look at or test the signal coming to my property, making this an inappropriate charge for what is clearly not an issue at my property or with my equipment.