I have a similar problem as highlighted by others on the forum. I had signed up for BT Broadband & phone (infinity1) package in July htrough the link on cable.co.uk which promised a cashback of £50. After broadband activation, I had filled up the claim form and received an email from email@example.com (in September) confirming the cash back and stating that I should receive it in 10-15 days. However, I have not received any this as yet and there have been no reply from them to my recent emails. I had contacted BT help and after their advise had fileld up rewards claim form last week as well but no reply so far.
Have you been able to reply to the Affiliate team by email? They should be able to tell you what's happening but if they haven't then we will be able to for you. You can get in touch with us by clicking on my username and then on contact the mods. It will take us a few days before we can reply to you but we will get back in touch.