I was going to call again but there seemed little point, even before reading the above posts.
Like Will Knot my application was also received on 15th March. Last Friday they were processing applications received on 8th March. And I'm guessing they won't be working tomorrow?
Here and on another forum it's been stated that cut off date for any grandfathering will not be earlier than end June. However it seems that is only what the CAA are proposing, and is subject to agreement with EASA.