No sense of urgency

I ordered a dress from the UK from a supplier called LemonLunar and it is sitting with customs to get clearance, Dawn wing needs a commercial invoice from the supplier, the supplier advised me that he has sent this with 5 other invoices together with my parcel when they sent it, I dont know why Dawn Wing cant find it but there is no sense of urgency regarding my matter, I have been emailing Nikki at Dawnwing and the supplier and calling the Dawnwing call centre, they dont seem to be making any attempt to get what they need in order to clear my parcel, delivery was supposed to be on Friday, I needed this dress for an event on Saturday, I paid R5000 for this dress to be able to wear it to a function on 28 October 17, and I didnt get my parcel in time, I am infuriated with the bad and slow pathetic service from Dawn wing, I am so upset with this to pay so much for a dress which I bought in time and then it was delayed by Dawn Wing, as they show no sense of urgency for peoples parcels!!!