Failed to deliver everything i ordered

This company offers free international delivery and there is also a range of good value kids clothes so i decided to place an order with them. The clothes were dispatched maybe a week later which i think is a bit too long but i didn't mind that much. A few days after the order is been dispatched i received an email from PayPal informing me that i received a partial refund from Adams which made me wonder why. I contacted the customer service( by the way,they don't have a phone number and the only way you can contact them is by email) regarding this matter and hoping all this will be clarified. I got a reply from them telling me that they didn't had all the items i ordered in stock and that's why i received a partial refund, because some items where not delivered. Wow.. it just made me wonder if this company has any knowledge of customer service??!! I would have expected to be contacted by them before delivering to ask me if i want to replace the items or cancel my order because i would have cancelled it to be honest. I sent them an email to complain about this but they never got back to me. I will never place an order with them again unless they improve their customer service and update their website regularly with products they actually have in stock. Its a shame because they claim to be a well established company.