Pro Connect Charge $100, Technician said it was “free”

Seems to be a disconnect with billing and technician.  I was told my visit would be no charge and a month later I see a $100 “Pro connect charge” on my bill.  If a technician visits me again I will require a written document of the actions completed along with itemized list of charges.  All I have is the work of the technician, which cox will not honor.  I read that this happened with other customers in the forum so it’s a systemic problem that cox doesn’t bother to correct.