I received a bill for 9.99 and do not know why

Be aware that if the only indication of a charge is from an email or text, it may be a phishing attempt to get you to respond and divulge passwords or other information.

You can use the following instructions to verify whether it is an actual charge and if so to see what it is for:

See your purchase history in the iTunes Store on a Mac or PC - Apple Support

and

If you see an unfamiliar iTunes Store or App Store charge on your bank, credit card, or debit statement - Apple Support

Also, one common charge for $9.99 is for Apple Music. That is charged after a 3 month free trial. If that turns out to be what you have been charged for and if you want to cancel, see: Manage your Apple Music membership on your iPhone, iPad, iPod touch, Mac, PC, or Apple TV - Apple Support

donnaspilt wrote:

I rec'd a bill for 9.99 for services and do not know why

What does it say it is for?