Hi @sjr7482, thanks for your post here in the Community, although I'm sorry to hear of your concerns raised here.
When a SIM is issued, it generally reaches you within the next working day but that is subject to Royal Mail.
The issue is, if we re-send another SIM for you and the one that's out in the postal system reaches you, that won't work once we re-issue it.
Have you received it today by any chance?
Many thanks
Tom_W