Mistakenly linked accounts

I called earlier and was supposed to be switched to the $50/5 yrs gig plan. Instead of switching to the new internet plan, a second account was added at the same address. Now, I assume I will be double billed.

Is there any way to cancel my original plan and keep the $50 one? I also have NowTV but will it still be free or will there be a charge?

I found out that a modem is being shipped as well, so I wonder if I can just keep the white one that is already connected.

Any help is appreciated.