It's so sad that people in authority think they can implement changes Ad Hoc, without notification.
ALL companies CAN make BACS payments to your account within 24hrs. They will always say they can't, what they mean is they are charged a fee
for making payments outside their normal payment window.
Stress to them the hardship you are incurring as a result of their change of premises and changing without notification the times and dates by which receipts and invoices must be submitted.
Explain further that if they do not pay up, that you will be seeking legal advice as they have broken the terms and conditions of your employment by changing things without adequate notification, and as a result you are going into debt, and may seek compensation for the said debt and the cost of legal representation necessary to resolve the issue brought about by the afore mentioned breaking of their terms and conditions of employment.
That is usually enough to make someone in authority turn around and authorise the emergency BACS payment.
Good luck hun.