Why handle Internation Brands when you cant get it right!!

I fail to understand why a retail business like WW handle international brands. They are ill equipped to do so, and then feed you lies, instead of resolving the problem. I ordered size 40 Birkenstock's on their website and I was delivered a size 41. When I checked the sandal, the SKU (price ticket) read size 7 and the size on the box read size 41. I returned the shoe to the Waterfront store for a credit. I then sent WW an e-mail explaining this size issue and I re-ordered the size 40 on their website. Unfortunately once again I was delivered a size 41. So I again returned the the item to the Waterfront store, where I was once again informed to re-order on their website, to which I refused as they had already failed to pull the correct stock twice.I suggested, they they pull the correct stock and I would rather collect from the store, as i was leaving for overseas. To date I have sent 5 e-mails following this up, to be told that they NOW don't have the shoe in stock. On the 6th e-mail I advised customer service that this was utter nonsense, as they had requested me to order again on line, when I was last at the store, and that the website does not reflect NO STOCK. I strongly suggested that they replenish the stock and fulfill the order as this is a running international line. To date I have have had a response from WW and must say this is a poor show on their behalf.