Cell reception/signal strength issue

How do I register a complaint regarding cell signal reception strength? 

Background-today Xfinity was working in my neighborhood to enhance the network.  Xfinity indicated the work was complete and no outages were present.  However my house has an outage still and I reported it.  I am forced to use my xfinity mobile data now to serve as my internet.  I have never had decent signal here but it has never really been an issue because of xfinity wifi being fairly reliable and calls and texts were fine.  Well that lack of a decent signal destroys any hotspot capability as it is just too slow.  So that lack of signal now haunts me. 

For several years over several phones anything Verizon/Xfinity cell strength has always been consistently very very poor here.  I do not live in a rural area but within a very large well populated area near major roads and even bigger cities without any terrain or structure issues to effect the signal so significantly.  I know signals only travel so far but this is a very well established area and better reception should be possible.

So I am just looking to register a complaint, long overdue, that reception in this area is substandard.  Is chat the way to officially document?  Maybe I am being too optimistic and there is no such thing anymore of trying to complain officially/document of poor signal or maybe poor anything.