Not straightforward

Still no acknowledgement email. It's now 8 business days since the parcel arrived in Sheffield.

On occasion, the email doesn't come.  But I PROMISE as your tracking shows it has arrived, it WILL be processed.  Are you sure of the email address the confirmation would be going to?  Have you checked your junk mail?

That's very reassuring, thank you. I have checked the email address I gave on the front of the online application form, which I imagine is the one they use, and it is correct. And I checked my spam - didn't find a email from Sheffield, but found plenty of other things that shouldn't have been there, including all the notifications from this forum. 

And today I gave up on receiving an acknowledgement email, so I pulled out my credit card, and rang the helpline, who confirmed that the visa application was awaiting a decision. They couldn't confrim if Sheffield have my email address entered correctly in the system (they can't see any personal details) but at least I know the application is being considered.