I was keen to send by registered post this time as when I emailed it last time it didn't get there.
Who told you to send anything by "registered post". Have you checked to see whether they were signed for? If someone refuses to sign for anything, all you then have is proof of non-delivery! What a waste of time and money.
How are you sure your email "didn't get there"? You can forensically prove that your email was delivered by the information in the headers of the sent email. Can you prove, assuming that someone actually signed for your post, that they actually gave it to the correct person or department or maybe they simply binned it. Who knows?
Sending anything by post to the court is fraught with issues. They are overwhelmed and it is possible that your snail mail letter is under a pile of other unopened letters.
In future, if you really insist on sending anything by snail mail, at least use the free, proof of posting service at any post office. That is all you need to prove posting. Two working days later it is deemed delivered and you can take that to court as evidence of having done your side of the work.
Did you receive a copy of the claimants bundle? (Their WS)
You should try calling the court first thing in the morning or better still, find the email address for the court (which you should have used in the first place) and email the court manager and ask what the status is of your case.