Change of delivery date without notice

Hi, I placed an order on 5 May and paid extra for it to be delivered this Saturday 9 May. I check my order now, and it says 20 May delivery. This needs to be delivered this Saturday... Order ***8. What's the point of paying for a certain delivery date, when you'll change it to 2 weeks later. Either refund me fully, or deliver this Saturday... I have inboxed you'll