Technical assistance extremely poor today!

Periodically our sets and our cells pick up out of state local channels through individual streaming applications.   I have called xfinity several times and the resolution was corrected in about 2 minutes.  I have been told repeatedly that the install tech gave us the wrong modem.  I have been told they can send me a modem for my programmed for our specific location. New modem never arrives.  So I call periodically to get local channels changed back to our state in about 2 minutes.  Today, 1st tech had no earthly idea what I was talking about and would switch me over to someone that could help.  He never did.  He gave me a phone number to call.  I call.  That tech said he would send me new modem if I pay shipping.  I once again explained that xfinity staff have told me I have the wrong modem and it thinks I am 40 miles south.  Therefore it picks up closer out of state channels.  I am not concerned with the safety of my family during high impact weather alerts in 2 other states.  I had been previously impressed with the technical assistance, lacking the fact I never received modem as promised.  However, today I experienced poor technical service that kept me hanging on while trying to find solution and failed.  Called number provided and he basically treated me like I was mentally challenged even though I explained we have had this situation occur other times and the local channel issue was resolved on the xfinity side very quickly.  He wanted me to pay shipping for a new modem to clear up inital tech install mistake. I said No.  He then tried to blame streaming service and asked if I called them and what did they say?  Considering 1 tv is pulling the local channels and 2 are not. (Always happens that way on the "set of the day.")  I explained I would call during the week for assistance.   Hopefully getting the "A" team.  Ugghh! Extremely frustrating!