Cable Card for TIVO

Our Cable bill increased a substantial amount when our contract expired. I called and talked to a customer rep. We signed up for another 2 years but the price was still higher than before the increase. I told the rep I was considering buying a TIVO as it would save us money on our cabe bill. She said just let Xfinity known when we switched to TIVO and we would no longer have to pay the DVR charge.  Today I made an appointment and went to the Xfinity store to get a cable card and I was told "We don't support TIVO anymore. You will have to use our DVR."  When I texted one of the reps this afternoon about the appointment she offered to send technicians to install the card. Is this correct? I see on the Xfinity sight that cable cards are available with self install kits. I'm confused.