Hi @Boatboy77 welcome to the community and thanks for posting, if you were eligible you should have got an email around 14 days after the order completed. Was the order placed online or over the phone?
Thank you for posting back. With the Xbox offer, there was a limited time after the order was placed that the Xbox would have had to have been claimed. It is 8 months since your order has was placed and I'm sure that has exceeded the timescales from the Xbox to have been claimed.
If you send me your details, I can take a look at this for you in more detail.
I have sent you a private message with instructions on how to contact me. You can access your messages via the envelope icon at the top right of the screen, or click on this link, Private messages