Gaston Luga only charges you with the amount shown in your checkout total, and you will also see the total amount in your Order Confirmation email.
If your card or bank account is showing a different amount, please check with your card issuer or bank if they may have applied any surcharges for certain special cases, such as for international or online purchases. If you purchased in foreign currency, please also note the exchange rate standard followed by your card issuer.
In case of a double charge, it may be that what you are seeing in your account is reservation or hold amount and not the charge itself. Please contact your bank for more information.