Canceling Service

My 88 year old blind and hard of hearing mother has not used her phone in several months. She is in a building that provided basic cable. She has a modem for internet and voice. I spent an inordinate amount of time on chat trying to cancel her account. The agent gave a confirmation number, and a bunch of other information. I asked for a transcript and was told when I closed chat I would be given an opportunity for a transcript. I closed chat and was offered not chance for a transcript so I don't have instruction providing options to return the cable modem, the final bill amount, the confirmation number (still haven't received promised e-mail with confirmation number) nor the 800 numbers. I pointed out that since the building provides basic TV there was some sort of modem that was turned in when the cable modem was set up. I said the basic TV modem needs replacing. I was told to call an 800 number, but of course, I don't have the number. I don't suppose anybody can help out.