Toys r us ******

On the 28th Nov 2019 I went to a toys r us store and saw a Bounce Travel System for R999 and they did not have stock, only the one on display. Today 29th Nov 2019, I went back to a different store and the price had doubled to R1999. Its black Friday and toys r us have prices going up to compensate for the prices that are dropping. All I want is proof that the price was valid till 28.11.2019, they were unable to provide me with that, instead a very ride employee Priya Govendor said prices are subject to change without notice. How?????