Since the actual shipping cost is not increased in linear order, our shipping cost calculation is complicated based on weight, destination, quantity, and shipping service. We need to split the shipping packages for every 4 items to make it small, and avoid importing tax at your country. Each pack has its own overhead cost, so the shipping cost will more increased for every 4 items. Then we will ship your orders one pack per day to make it reach you at the different days. So, it's normal that you will NOT get all shipments at the same day. The shipping diagram is shown below: