It sounds as if we've registered Quidco as the referral site. Did you clear all of your cookies and cache after closing the Quidco page or just close the page? Also, were you logged into the Quidco site? If you were, I'd check it to see if anything has tracked with them.
@Walsh50 you don't have to be logged in as your browsers cookie setting record the site that you have been viewing, this information needs to be correct for the cashback to track and it's recommended to delete your browsing history and cookies to ensure it tracks correctly.
I'm afraid this is something that BT have no control over and TopCashBack do explain this in their FAQ's and help section. If you have any complaints you'll need to raise them directly with TopCashBack.
@Walsh50 I'm sorry you feel that way, if you speak to 0800 800 030 they will be able to cancel. We could raise with the cashback team if you send in your details on the contact the mods link but I can not guarantee they will be able to help if the purchase tracking is incorrect with TopCashBack. If you click my username you'll see the link.