Have a look at your account to see what you are being charged for.
I can't think of anything offhand that attracts a fee of $9.90 per month. Maybe Selling Manager Pro if you don't have a store.
Anyway, as I said, have a look at your account and that will tell you exactly what you are being charged for. Then unsubscribe from it. Maybe ring eBay and see if they will waive the fees for whatever it is that you chose to pay for, but now longer want to.