double billing

Common causes of what looks like double billing are:

1. A previously declined payment was charged again later, so the late payment and the next on-time payment appear close together.
2. More than one Microsoft account is using the same card.
3. Recurring billing is enabled on a subscription.
4. A family member or someone with access to the card made a purchase.

To resolve it:

1. Sign in to the Microsoft account and review Order history for multiple purchases of the same amount close together.
2. Go to the Manage your payments page and select Investigate to look into an unrecognized or duplicate charge.
3. If the charge does not appear in that account’s order history, check whether another Microsoft account is using the same payment method.
4. Compare the last few months of bank statements with the Microsoft order history to confirm whether it is a true duplicate charge or a delayed retry of an earlier failed payment.
5. If the charge is still unexplained, use Contact Support from Microsoft Support for billing help.

References:

• I've been charged twice | Microsoft Support
• How to investigate a billing charge from Microsoft | Microsoft Support