I want to dispute a service charge

I want to dispute a $100 technician service charge.  When I signed up, Xfiniti said the residence was capable of self install and no technician was required.  I received the equipment, did the self install and the service would not work.  A technician was dispatched and upon his arrival, he said the equipment shipped was not the correct equipment for the service that Xfiniti provisioned to the residence.   He had to check multiple lines/nodes in the neighborhood to get a signal, then had to use equipment in his truck to get the service to work inside the house.  He said that the equipment shipped to me for self install would have never worked with the service in the neighborhood and provisioned to the house.

So the technician dispatch/charge was necessary and should be borne by Xfiniti/not me as I had no control over the lines/signal coming to the house and the wrong equipment for self install was sent.

Thanks,

Dave M