$100 technician visit was charged: inspite of the fact Xfinity told me there will not be a charge

Called Xfinity because of the problems with TV picture.  They did some trouble shooting on the phone/remotely and told me they will send a technician:  they told me there will not be any charge.

Technician came and replaced the TV/xfinity box, that fixed the issue.  The technican also told me no charge becauge it was Xfinity issue.

I still see the $100 fee for technician recorey fee on my current bill.

I contaced at least four times (once thru live chat and 3 phone called):  They all said the fee will be waived.  Last two phone call: they told me it is taken care off and gave me confirmation numbers.

I stillsee the $100 in my bill It is still not waived.

This is frustrating.

Calling the billing agin does not seem to help.  

Who do I need to contact to resolve this billing issue?