Your hearing date is 22 June
The claimant has to pay the fee by 12 June
You and the claimant have to submit Witness Statements by 8 June
You need to prepare your Witness Statement, but I suggest for now you research what this is and how to phrase it, and plan on its structure. A “skeleton” Witness Statement if you will.
DCB Legal has the same deadline, so I would not suggest writing a full Witness Statements until you receive theirs first, and you can use points in your Witness Statement to disagree with theirs.
It is likely they will discontinue, which may well be before 8 June, to avoid them the bother and expense of submitting their own Witness Statement. But it’s best to be prepared in case they do submit one, and then you submit yours, and then it is likely they will discontinue before having to pay the fee on 12 June.