given wrong sizes now there is no stock

Bought 3 paid of Nike sneakers from Cross Trainer Maponya Mall.i requested for specific sizes but I was given incorrect sizes.I only realized when I got home that I was given wrong sizes.now when I went back to the store to return the shoes,iwas told just how they don't have bigger sizes in the shoes I bought and that bigger sizes would cost me more.the sad part is Thobeka didn't even want to come to explain what she did and apologize.My kids do not have sneakers for Christmas because of the incompetence of your employees.i bought 4 pairs 3 of then my kids can't wear.this is completely wrong.i demand to get what I paid for and before Christmas!