You apparently have an account with Zooplus. Just login to see what you ordered and which invoices have been sent to you. If the final demands from Zooplus have gone over to debt collection, your account is then (by them) set to zero. If you contact Zooplus, they will then likely tell you that there is no debt any more. This, however, is incorrect. These employees have no access to the credit management section of the admin.