I think you may find that the claim cannot be processed, until you are outside of the cancellation period.
The claim may be submitted, but would not be authorised for payment until you were outside of the cancellation period.
I expect you will get an update soon, now your service has been activated.
Hi @iceblues I've raised another case with our partner promotions team regarding your cashback claim, as soon as they update me I'll get back to you. I would also recommend you raise a ticket through the Topcashback site to make sure this is not a problem on their side.