I sent some test emails, but they went through without a problem. Did you send the email from the email address that is registered to your account?
In any case, it is usually best not to discuss billing in this public forum. Please try sending your question through the "contact us" form, under "Help" (at the top right of the page in your Vendio account) --> "Contact Us" --> "Email / FAQ" --> "Contact Support" --> fill out the short form and follow the steps.
If you would like us to confirm that we received your message, please post here and we will check.