I'm confused about phone they sent

So about a month ago I talked to an online person from Comcast,my Internet bill was high due to too much Internet so they charging extra fees.they said there's a unlimited plan.but he said I can get the plan if I take a Motorola phone.i said I don't need a phone.i don't want to pay for cellphone coverage every month,I already have a phone.he said I won't be billed every month or billed for the phone.but if u want the unlimited Internet plan for home I need to take the phone.so I said ok gemme the phone.on the bill it says I'm paying for the phone every month.im trying to figure out if they charging me for cellphone coverage every month? I can't seem to find it in billing.if I turn on the phone will that activate the mobile billing? Is the phone unlocked? The phone is sealed in the box ATM.