This is exactly why I do them recorded delivery.
I've just checked all the 3 packages I sent out yesterday, and according to the post office site neither yours or one going to Stevenage has been delivered.
On the site all it says is that they were 'accepted' at the post office where I posted them.
The third one though, to one for Nudzy says it was delivered from the Norwich post office depot and has since been signed for...which it clearly has.
I can give you your Tracking number via PM if you like Kizz. I'll also phone them tonight to find out what's going on.
They should be fine with the extra day in transit, but I'm still not very happy with it basically telling me it hasn't left the post office.