Makro not honouring their word and irritated management

I went into the Centurion Makro branch to look at a Weber braai advertised as R2999 on sale. I was unsure whether I wanted to spend the extra cash on a better Weber and asked a staff member till when the sale on the Weber was running, she assured me that the sale is until the 13th of September and I therefore decided to take some time to make up my mind. I returned back the next day (04/09) to purchase the Weber that was on special. I was told that the special was only valid on 03/09 and that the person that assisted me refered to the wrong special. I confronted the store manager about this and he was not willing to sell the braai for the advertised price that the staff member assured me will still be valid. The store manager also started to take an irritated tone with multiple excuses when confronted on his answers, I was very respectful, polite and direct in the way I confronted him. According to me it will be ethical business to honour the promises of your staff members (even though they unknowingly misled you) and also to not run specials in such a confusing manner. I decided not to do business with them as a matter of principal and got a way better deal on Takealot for an even better Weber.