I also have the same problem with no voucher received from BT when clearly advertised with the mobile offer as shown in the copy emails below.
Further to the customer support email just received, copy below, Yes I am a dissatisfied customer of BT when I am not receiving what is advertised. My Mobile number is xxxxxxxxx which is part of the overall contract which I have with BT for the account of xxxxxxxx . I notice from the several BT customer notice boards that I am not the only long standing BT customer who is struggling to get what I am entitled to in the offer when switching to BT Mobile. Perhaps I may be better passing the matter to the Martin Lewis Money show and let him investigate and highlight the issue, As can be seen from my email in June 2016 I was promised the £30 Amazon card and this as of today 17 July 2016 17.13pm has not arrived,
I am happy to discuss this with someone.
HowardB1 (BT Customer for 22 Years)
We’ve received an email reply from you relating to the incident reference number shown above, however the email address you sent it from doesn’t match that of the original enquiry.
If you’re a BT customer and wish to reply to an email from us, please use the email address you originally used. We’re sorry for this inconvenience, but it’s necessary to protect your privacy.
I'm sorry for the delay receiving the £30 Amazon voucher that you signed up for as part of your order for BT Mobile. I have moved your post to start your own thread as that's the best thing to do.
Can you send us over your details so that we can chase the voucher on your behalf and make sure you get it as soon as possible? Click on my username here >> RobbieMac << and you'll see our contact link on the left hand side underneath my profile picture.