When you purchased a hosting account and through your Client Area, you were offered to choose the payment frequency that suits you best among the following options: Monthly, quarterly, semi-annually, or annually.
The same choice is offered when you decide to change hosting plan (page "Upgrade/Downgrade your hosting plan").
... But if your product was purchased prior to the opening of the client area and billing system, you did not have the opportunity to make that choice and your default payment frequency is "Semi-annually".
If you are in this situation, you can always opt for a payment frequency that suits you better, but you will have to ask us to make this adjustment, either by email (support@webinfologic.com) or by opening a support ticket from your client area account.