Router Sent but charged

[Sumit1]

I had requested a new router and the same was returned but I have been charged for the same in my November invoice

[RobertP]

warum bestellst du erst einen Router und schickst ihn dann zurück?

[reneromann]

Just sending it back does not constitute a withdrawal ("Widerruf") in case you wanted to withdraw from the rental agreement...

That would've needed to be done exactly as stated in the package using the online form -or- reaching out to a special email address -- only sending the device back is not sufficient enough to withdraw.