This DDJ has basically caused problems because it is not usually the case that witness statements have to be submitted so far in advance of the hearing. Normally, they are expected to be sent no later than 14 days before the hearing date, which means that the hearing fee is due at least a fortnight before the statements. As they normally discontinue just before the hearing fee is due, there is no need to waste time on a WS.
Hopefully the letter will get the order set aside and a new order will be issued. However, even if nothing else happens, you have over three weeks to submit a WS. Plenty of time to prepare.