Where is the complaint department

After connecting  my phone looses audio out after seveal minutes.  It`s a Moto e6. has anyone else had this problem?   I called Tech Support - waited and waited when I fianally got someone the phone stoped working.  I tried several more times bfore I got through to a technical support representative.  We agreed my phone would be reset and I would try it for a day see if the condition was curred by the reset.  He said he would call me at 11:30 AM today.  The problem is still there and he did not call.

I contacted tech support via Chat  and arranged for retuen of the phone. After a few minutes of consideration I decided I wanted to go to a local xFinity service center and asked the Return Authorization be cancelled.    He said he was unable to do that.    I just called the local store and made an appointmnet for 4:15 today.   Has anyone had a problem returning a phone that does work properly?