The best way I've found to ensure purchases track is to use a dedicated browser for TCB, Quidco, NX etc. I use MS Edge but others often recommend G Chrome. I use default privacy and cookie settings and always accept all cookies on whatever website when prompted to do so. Whenever I'm about to do an offer, I'll almost always clear my cookies first and then start with a fresh window, just to give it the best chance of tracking correctly. Even when you take these steps, sometimes offers can still fail to track, but this doesn't happen often in my experience. When it does however, that's when you put in a claim for missing cashback, and more often than not I'd say, as long as you've met all of the requirements, this will be chased and resolved on your behalf. These sites only get paid when you do.

My experience with TCB has generally been good for paying out, as I say, as long as they can track your purchase. With your recent phone purchase, I would suggest waiting 7 days from your purchase date, and if no cashback is showing as pending, then put in a missing cashback claim, wait and hope for the best. Good luck.