Unfairly treated

I went to Crocs in Access Park in Kenilworth today to purchase my Mom some slipins .Saw a nice slipper for myself marked @99'95 There was a few on the sale wall as you come.into the store 2size 4s and 1Size 5 .I was interested in size 5 took it because I thought WOW this is a bargain it is a summer sandal but I can hold it until next summer . Got to the till and the Cashier says to me it is marked the wrong price I them challenged him asking am I not suppose to pay what I see and what is *** cashier left and went to find out why the size 5 of the exact shoe is marked a different price that the size 4 he gave me a lame respond that did not make sense .I left furious because the Cashier did not evens involve his manager as per what they can do to satisfy client .And I left furious why because as a valued client I was not treated well .. I made it my duty to tell the Cashier so why are u not taking the other stock off the walk and Mark it correctly as I saw two ladies at the wall while I was paying for my stock looking at the same slipper .