Contacting county court to withdraw an application, hearing is looming

[countycourthearing]

I applied to the county court for possession of a property (long story but tenant gave notice then stopped paying rent and refused to move out, was destructive etc). NRLA said to continue to pursue unless/until I had vacant possession. Tenant evenutally moved out just before Christmas so I contacted the county court (hand delivered letter and email) to ask to withdraw the application.
The phone hasn't worked in months, there's always a recording saying the call can't be connected. The court date is rapidly approaching.
If they don't get in touch what can I do? Should I attend in person and tell them the tenant has moved?

Did you get a receipt for your hand delivered letter and a read receipt for the email? If not repeat.

Thanks for your reply. No reciept for letter (I was told to leave it in the drop box) but I did get an automatic reply to the email, which says to expect a reply within 10 days (hearing is scheduled in less than 10 days).
I'll go down tomorrow and ask at the door (will bring a duplicate letter and ask for a receipt) but afaik there is just security there. Hoping they'll be able to advise.

'receipt'