Shocking customer service

I bought a pair of Hey Dudes for my husband for Christmas from a stockist. The shoes I bought (UK10, even though he usually wears a UK9), were too small. I phoned the store to exchange, but they did not have his size. They phoned their other branches, but did not have one pair in a UK11. There was even no stock on their online store. The store only offered exchanges and not returns and they told me to keep an eye on the online store for when they restock. Up until now the don't have new stock. I phoned the Canal Walk store to hear if they could exchange the size 10 for an 11 - exact same model, just a size up. These shoes have been tried on once and never been worn. They could not assist me. I phoned head office, who import the product and they could ALSO not assist me. They advised that stockist's couldn't order specific styles/sizes; they were sent to the stores in bulk and they "get what they get". Therefore I cannot exchange the shoes. The store I bought them at's branch has closed in the meantime. How can you just say "sorry, there is nothing we can do"?? I asked to speak to a manager and was told "it will just be the same outcome." How is this customer service? Surely there is something that can be done? Absolutely shocked at the lack of willingness to help!!!