Online store poor service

Hi, I fail to understand how your online store works as I entered my details to be notified for the Adidas ZX Flux Copper sneaker SKU ID: ***8 a few weeks ago and every time I go online, it's out of stock. Every time this sneaker goes off your website and then when I check again, it's back on the website but out of online stock; however, I got no notification to say that the sneaker is back. Surely if one entered their details to be notified, I should automatically be notified once it becomes available again but this has not happened! I am utterly disappointed in the service received as I was told this morning by a sales consultant at the V&A that they have ordered a size from up country for a customer and when calling the stores as well as online, no one mentioned this to me. Again, how does your online work and why was I not notified when the sneaker became available again???What is the point of having the email me when available option if this does not let your customers know when a certain item is back in stock. I have been asking about this sneaker since last month as I was told by Adidas online that Sportscene would be getting in stock and since then I have been calling.