How to downgrade add-ons and edit how many sites I'm paying for.

I deleted a website 3 months ago and am still being charged for the add-ons I had with 2 sites.  My payment has not changed.  How do I downgrade the add-ons and edit how many sites I have?  It's very easy to add items, but there is no help on deleting items.  There is no "contact us" or "help desk" to send a question to other than posting in a community and hoping it gets seen and answered.