Logistical nightmare!

Placed an order for toys on the 18th of Dec for xmas with these guys, package arrived 2 days later with one of the items was left out of my package, despite showing in stock on their website and after receiving confirmation from a sales lady that it was in stock. Now I've been trying to make communication with them , message after message, surety that they will call me back asap and they never do. I've now been asked to send photos of the package that arrived to prove that I didnt receive this item?!