There was an issue a few weeks ago affecting a small number of prize redemptions, which were failing to process correctly after approval.
You can see a post from 13th September here:
https://www.facebook.com/groups/1113007912133282 and a reply from me about it, including confirmation that the problem had been found and fixed on 14th September.
Most if not all players who had reported this issue have resubmitted their redemptions since then, and successfully received them.
The timeline suggests something like this may have happened to you. If the SC have not been returned to your account, please email support and ask for it to be escalated to the General Manager, referencing this thread.