make a complaint

My internet went out yesterday and when I called customer service they said someone would have to come out since it does not appear on line and it would be the 29th (6 days).  I explained that I work in healthcare from home and need my internet for this purpose.  After a lot of escalation I was given a day of the 26th (3 days out).  The next day, the 24th, I received a call from Xfinity saying my service should be on, they detected a problem with my area.  It did come on and the agent told me he would need to cancel my appointment for the 26th since it was working.  In about 15 minutes after talking with agent, my service went out again.  I called and was told, once again, I cannot have an appointment till the 29th.  I explained again that I need my internet for my healthcare job, and once again, this was escalated.  I was transferred to Lisa in escalations.  She told me she cannot do an appointment until the 29th since I cancelled my 26th.  I explained the agent cancelled and it was only 15 minutes ago.  I also explained about my position and I cannot go without internet for my job that long.  She said that is irrelevant you cancelled your appointment because your service came on and she could not get me an appointment till the 29th.  I again explained I did not cancel the agent it and also about my job in healthcare and needing to be online, and once again, she told me that is irrelevant.   She was curt with me, unconcerning and told me she would call me back when someone calls her back, but if I don't hear back I have my appointment for the 29th.   My job is not irrelevant!   I never had such unprofessional agents from Xfinity in the past, expecting someone to wait six days to get service when I am expected to pay you on time!   I will be looking elsewhere for service.