Hi AEJ
Thanks for posting and welcome to the community.
Depending on when and what changes you made, they may take thirty days to apply. This would be if downgrading/disconnecting a service etc.
In this thirty day period, you may have a bill based on the old package price. We do advance billing, so you may see the bill with dates after the package changed on it. As such, the bill after will contain any pro rata credit owed to you.
Does that explain it?
Kind regards,