If you see multiple charges in the "Authorized" section of your online banking, any extra preauthorization charges should disappear after a week. If you're seeing multiple "Completed"/"Posted" charges, see below.
If you switched versions within a month of your last payment, you may see the second charge before the prorated refund for the first appears. It may take up to two weeks.
You could accidentally have multiple subscriptions charging for the same Rapid Resizer account. Or you could have multiple separate accounts (husband and wife with separate accounts, e.g.) but that are being billed to the same payment method. Please contact us to sort it out.