Always out of stock, always excuses

This will be the 5th time that when I am due for an upgrade you guys never have stock of the phones/tablet that I want. I have phoned 5 stores the whole of last week looking for a Samsung Galaxy tab s2 or tab a with S-pen an none of your stores have any. I then get told that stock would arrive on Thursday 26th which obviously did not happen. If an item is popular, ensure that you have adequate stock, if you know that you are going to have shortages, STOP ADVERTISING THINGS THAT YOU CAN'T SUPPLY.