Thumb sucking the price

Northgate ackermans service i went to do shopping for my son and he wanted this bag so bad got to the till there was no price and it was the last bag they had so i waited for them to try and locate the price of which they couldn't due to the fact that it was an old stock, but i needed the bag anyway. The bag was torn and told them i dont mind buying i will fix it. The manager then decided to make up the price and sold it for R69 my shock is he thumb suck the price and never consider the fact that it was torn.