Router scam

[BeePee]

I have been threatened with a debt collector for none payment of a 5g router that I have returned as requested. The label had been pre-printed by Three with my name and address printed and a reference number. I am told this is a unique number related to the return, I am also told that without it they cannot confirm it was returned. 
Surely my name and address would be enough as it was on the label. 
I was told, even if the return was scanned, they could not confirm the return, it makes no sense. They just default by charging you for the router, if it wasn’t a recognised company I would think it was a scam. Or it proves that even well known companies scam you, I know this as I am not alone getting scammed by Three. 
please advise on my next move as I no longer have the reference number and this number does not even prove receipt of the package.

[Maxine]

Hey BeePee,

We've sent you a little PM about this.

To view your private messages on the community, click on your avatar image in the top right of any community page, then "Messages".

Maxine

[JonathanB]

Hi @BeePee,

Did you manage to get in touch with the team Maxine mentioned? Please let us know if this is resolved now or if you need any more help?

Thanks,
Jonathan

[Paddiewack]

So did you return it or not? With all your “scam” x 4  rhetoric it’s hard to tell. 

[BeePee]

• Of course I did, it’s not rhetorical, it’s my opinion on the way they handle returns. It seems they are returned to a third party who fail to record the returns. This is based on the conversations with the customer service answers I got.

[Paddiewack]

Well at least this time you omitted the word “scam”. That’s a refreshing change!