fios wireless router return question

I had a problem with a wireless router and requested a replacement that I successfully received.  The paperwork that came with the new router said that I did NOT have to return the old wireless router because Verizon does not support that particular model anymore.  Fast foward a couple weeks, I receive my monthly Verizon bill and on the bill it states that I have to return the old wireless router or get charged $99.  

Why did I get conflicting information?  What am I actually supposed to do with the old wireless router?

Re: fios wireless router return question
Champion - Level 1

Your issue has been escalated to a Verizon agent. Before the agent can begin assisting you, they will need to collect further information from you.Please go to your profile page for the forum, and look in the middle, right at the top where you will find an area titled "My Support Cases". You can reach your profile page by clicking on your name beside your post, or at the top left of this page underneath the title of the board.
Under “My Support Cases” you will find a link to the private board where you and the agent may exchange information. This should be checked on a frequent basis as the agent may be waiting for information from you before they can proceed with any actions. To ensure you know when they have responded to you, at the top of your support case there is a drop down menu for support case options. Open that and choose "subscribe".
Please keep all correspondence regarding your issue in the private support portal.