@Kate_A Quidco have confirmed that they will be issuing the credit the Quidco account. It can take up to 30 days. I'm not too sure at what point the purchase will show as "tracked", but you're definitely getting it, as confirmed by them.
I'm sorry it took us a while to get confirmation.
Thanks for all your help, the cashback was paid into my Quidco account last week thanks to your efforts!
Great customer service from BT. I only wish the same could be said for Quidco!
Thanks to BT and all your help in resolving this.