Issues with technician

My tech arrived yesterday unannounced to my home and walked into my bdr door did not introduce himself and was there to check speedsand connections. According to Xfinity assistant 

“We checked the line signal coming into your home and found an impairment that is causing connection issues. Your gateway is online but is experiencing signal degradation on the network path.

What we're doing: We are arranging for a technician to visit and repair the connection to your home.”

proceeds to tell me nothing was wrong refused to do his job and cussed and left leaving the apartment and did not fix issue and was unsafe and unhinged, how can I report this?