Gig Speed - avg 100mbps

Recently upgraded to gig speed interent from 200 mbps.  Internet was performing very well (to the plan) and nearly reaching 200 on every device at all times.  Within an hour of upgrading, internet speeds dropped to on avg 100 mbps.  Upon investigation, my previous netgear router/modem combo device did not support gig speed but still supported 800+.  So, I purchased a new modem and new router to better support gig speed and faster (should I need it in the future).  

Upon installation, spoke with xfinity support to ensure device is configured properly on their end.  Was told, "you are all set up and you should see your new plan speed within an hour or so".  About a week and half later, 2 phone calls, 2 chats, and about 7 hours spent on the phone/chat still coming in around 100mbps.  Ticket reference number CR913340245, never received the 24 hour call back.