The Federal Court has ruled that the Billag fee is not unbinding tax. Retrospectively it is not reimbursed - at least not further back than 01/04/2015.
If a company has already paid for the financial statements for the period starting with 1.4.2015, the sum is deducted on your next bill credit. It involves the refund of VAT. This credit should be recorded as 100% tax refund. The new-billed fee is recorded for the future without VAT.