Cisco DPQ3212 Rental Fees?

I had a technician come out in April and change out my modem. He told me that if I used my own router that I could avoid the $6.99 per month rental fee, so he put the Cisco DPQ3212 and I connected my own Netgear router. But I am still be charged the monthly fee. I contacted Cox twice concerning this and they don't seem to understand what I am saying. They keep telling me there is a modem rental fee no matter, but there is only a fee for a wifi modem (modem/router combo) which I don't have. I saw another post on here regarding the same thing and it said there is not suppose to be a fee. Can someone please check on this for me?

Other post:

Hi,

I just swapped my old DOCSIS 2.0 SBV5222 for a DOCSIS 3.0 DPQ3212. I am subscribed to both high speed internet and digital telephone. I was assured there would not be a rental fee for the DPQ3212 when I ordered it, since I have digital telephone as well. I never paid a rental fee for the SBV5222 either. On my bill I see two separate Gateway Modem Equipment Fee entries now. What is that? I thought there was no rental fee? I don't want the DPQ3212 if there is a rental fee, besides, the old SBV5222 was doing just fine. I would rather just keep the SBV5222 with no rental fee than keep the DPQ3212 with a rental fee.

Thanks,

Gopalan