lying to clients

I have visited their store today to buy a Jojo Tank advertised on their first page of their pamphlet for special running from the 24 September to the 10 October and I have been told that I can Not buy it as the once they have on stock did not buy it with a special price from Supplies hence i can also not buy with their advertised price. The catch is they can't even tell me when will they receive stock. I have bought lot of stuff from the same store it is very sad when I have to take advantage of their specials I can't, not because of no stock but because of their profits vendetta. Bad service