Changed plan and my bill is now way too high

The confirmation email I got when I made changes to my account says my new Estimated Monthly Bill is $256.15 / mo.

Today, I got a bill for the following:

Partial Charges: $124.45 (I understand this)

Regular Monthly Charges: $489.80 (I don't understand this at all)

My old plan was the X1 Premier Triple Play which was $215 / mo.

It looks like the old X1 Premier Triple Play package was NOT removed from my account so my new plan plus my old package is still on my account.  How is it even possible to have two separate plans / packages on a single account?!?  However, even doing the subtraction $489.80 - $215 is  $274.80 which is still almost @$20 higher than what my confirmation email said.

I really need an explanation on this.