If you have received a debt collection notice for an unpaid invoice, you should have received a original invoice a while ago. The notice has not been sent to an external debt collection agency yet. This is just a notice that the invoice will be sent to a debt collection agency if it is not paid by the due date.
If you would like to complain or already have paid the invoice, please use our contact form and attach documentation for the payment. You will find a receipt for payment in your online bank, the receipt must include IBAN and SWIFT.