I received a letter on 5-30-18 that I could receive a new modem free of charge by mail. I went online and couldn't find the necessary place to order the new modem, model no. TC8305C. Please advise.
That gateway needs replacing, for sure.
For faster service, you can use Chat support or call 1(800) XFINITY , otherwise, stay put and hopefully a Comcast employee will get your request started here soon.