I don't use my digital phone service, and I can't turn it off

Others have posted about not using their digital phone service, but still paying the monthly charge for it. Cox's explanation is that I am getting a multi product discount (aka bundle discount). I know that on my bill, I am paying $18.39/month for a service I don't use. With the increasing use of cell phones, why doesn't Cox "bundle" the internet and TV and give customers the option of turning off their phone service and saving the $18.39/month. I feel like I'm being scammed.