Complaint

Hello i have bought soccer shoes at mr price sport at kolonnade retail park,on the flasher it shows the amount of 400 and when i went to the counter price increased to 480,i found it unfair on my side while i request to pay the price i saw on the shelve"the manager rep**** to me as"is either i am paying the price system requires or i can leave the shoes since i had no choice they i paid their price