Order placed with in stock items, for an expected date, now suddenly there is no stock and my order get split etc

Order placed with in stock items, for an expected date, now suddenly there is no stock and my order get split etc. what am i to do arriving at a birthday without the gift? And delivery is just as bad, either too many boxes or items not even boxed, for everyone too see what you ordered, no privacy. But the advertising in stock and then delaying the order is very bad. So frustrating.