Unstable, unreliable internet service

I am currently paying for 1g download and 20mb upload.  I am lucky to get 200mb download speeds.  The speed is not the real issue.  My internet modem disconnects and resets multiple times throughout the day, kicking me off the internet.  My ping fluctuates from 20ms to over 2000ms constantly.  I have had my modem replaced several times which seems to fix the issue for a few months, then I have to navigate though the horrible AI customer service to figure out how to get another new modem?