Why has my internet been out for the past 3 days?

First. Check here for official info on any local outages;

https://www.xfinity.com/support/status 

Use a cell phone internet service, a public WiFi hotspot, or a neighbor's internet if you need to in order to check it.

Or you can use the Xfinity App: https://www.xfinity.com/apps 

Good evening @user_tuxx9s, and thank you for reaching out on our Community Forums with your connection issues. We're sorry to hear your internet has been down. To confirm, is it back up yet? If not, are the modem lights on, off or flashing? 

I also see that you stated your price has gone up twice in the last six months. It sounds like you may have been on a promotion that has now expired. We'd be happy to look into new promotional offers with you. If you'd like us to help with looking into current offers, please send us a Direct Message with your first and last name along with the service address on the account including any applicable unit or apartment numbers.

To send a "Direct Message" ("Private") message: Click "Sign In" if necessary

• Click the "Direct Message chat" icon
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
• Type your message in the text area near the bottom of the window
• Press Enter to send it