With all the issues surrounding these cashback deals and the chances of certain companies making it hard to claim I thought I would post this up.
Carphone Warehouse operate a Cashback Promise -
When you buy a new handset from the Carphone Warehouse, not only do you get the best deal on the web*, but we guarantee to pay your cash back claim**.
There are many websites offering a deal too good to miss on a contract phone, but make it difficult to claim the cash back or simply dont exist when payment is due.
Our promise to you is that we guarantee to pay your cash back now, and in the future.
Alongside this they operate a Price Promise -
We believe we offer the best deals on the net, but in the unlikely event that you find the same product cheaper anywhere else, let us know and we will match it*.
So it would seem to me that if you find a nice deal on one of the more problematic companies then no problem - approach CPW.
I hope this isn't common knowledge and I've wasted anyone's time - Just trying to help :D
*Mod edit - moved into this forum, as it wasn't really a deal as such*