Do you still have proof of shipping the package?

Yes, I have the shipping receipt from PostNL. But just according to the email, it seems KPN was saying they only received the equipment partially or I understood it wrong? I am pretty sure that I have all the equipments put in the return box.  

Complete your profile and an employee will look in the system and give an appropriate answer. Due to crowds, this may take a while.

ok, thanks. So for now I should just wait and no need to call them, right?

You can call 0800-0402, but you can also wait for a response from an employee. This may take a while due to crowds.

Hi @Jooooo, welcome to our forum. If you gave returned both tv-ontvangers already you obviously can't send it again. You don't have to do anything, you can ignore this letter. I've checked the system and the hardware has been marked as received.

Thanks Jasper for the confirmation.