Pathetic and false adverti*****t.

I bought sandals on the 17July 23 that was on sale however they did fit organized the exchange and was accepted and was picked up on the 26 June and I was only informed after I follow up yesterday that I will received pair and the refund for the other one because its out of stock ,why would they process the exchange knowing they don't have sizes and still this far haven't received sandals that was couried last Tuesday.