I keep getting 4 different charges of $9.99 on my mobile phone bill. I have no idea what this is for

Are your Apple App Store purchases paid from your mobile phone bill? If the are, here is a one-stop link for billing questions→Subscriptions and Billing - Official Apple Support. You can review your purchase history to see what you were charged for, cancel subscriptions and request refunds.

If they are not Apple charges you need to contact your carrier to discuss your mobile phone bill.