I am truly sorry for all the confusion and any misinformation received, however upon checking, your landline service is not set up on VOIP just yet, so your handset would not currently work when plugged into your Hub.
According to our records, I can't see that your area has been upgraded to support VOIP yet. This would explain why you have not yet received a letter or the adapter originally.
I'd advise to wait until you receive further notification of when your landline service is due to be upgraded, and further instructions on what the next steps would be, will be included in the letter.
However as you've mentioned that your landline is not working when plugged into your wall socket either, we will need to arrange an engineer visit for you.
I'm afraid that we do not offer landline handsets, so it isn't something we can send out to you I'm afraid.
I've sent you over a private message so I can take your details and book in an engineer visit for you.