Unfair Display payment

We got to the store to buy a washing machine 13kg Lg that was displayed and on the machine it was written Was R5500 Now R5999 Last chance Save R500 Soo now they saying we must pay R5999 which meabs we are not saving R500 as displayed now they say it's a mistake from Head Office of which we have nothing to do with their head office.. I'm unhappy as a customer instead of saving as thzy said ive paid more they only gave me store apology of R300 given the situation in the Country i can't be paying soo much.