Upgraded Modems and now internet is terrible

I called Xfinity for a billing issue, after that was settled the lady told me my modem XB6 (TG3482G) was old and not fast enough for my speeds anymore and said she would send out a new modem (XB7).. I tried to set it up on Friday night after work, it wasn’t working, would not complete setup via the Xfinity app.  So I left the old modem hooked up.. I’ve never had a single issue with my old modem.  It was still working for Friday night.  

I tried hooking up the new modem again Saturday and still would not work. I called and they said it was still showing a pending order and completed the order and that it should be working.. it kind of worked for about an hour, phones/iPad would connect and work (even with cellular data off).. but TV and game consoles would not connect.  I called back, they tried to reset it, wouldn’t work.. they escalated to a higher people and said they would be sending signals to the modem for the next hour and when done, it should be working and if not reply to the text I receive and someone will call me.  Surprise it didn’t work, at this time it was almost 12 at night and I did not want to be on the phone anymore, so I waited till the next morning (Sunday) and when I woke up the internet was in full blast working and everything connected including our ring system after being down all day Saturday.  So I kept the text just incase it went off.. and guess what, we went out for the night and when we returned home the internet was off again and not working at all. 

Again, I called them and they couldn’t help me at all and setup an appointment for a tech to come out and told me they would be here today (Monday) between 8-10am.. I agreed and they continued to send me over 50 text messages over the next hour.. after 30 minutes I had to call them again because they were not stopping. And it was all about setting up an appointment and charging me $180/month for TV which I don’t have and never asked for.  I called and while on that call I received 17 text messages.. they finally stopped.. and then I got an email saying my appointment was for Tuesday which I initially declined because I have to work and they agreed to send someone Monday morning which was obviously a lie.. so now I had to reschedule for Friday, so now I have to wait a week for internet and my GF is in nursing school and needs it for classes and homework, this is totally unacceptable. 

I never had an issue with my old modem and I requested to go back and use the old modem while waiting for the appointment that is now a week out after being blatantly lied to… and I was told I could not.  This whole situation is beyond ridiculous and is extremely frustrating.  

this morning the internet was again working flawlessly and again about 5pm it completely cuts off.  So I get internet in the morning until about 5pm which everything works fine including my ring system.. then after that nothing works until the next morning.  

Has anyone else had this issue when “UPGRADING” modems???