I purchase a bootleg jeggings from Mr Price - Gateway, two months as attached in the pic

I purchase a bootleg jeggings from Mr Price - Gateway, two months as attached in the pic. I took out the jeans last night to wear, however upon taking it out , I saw the size on the jeggings was incorrect The size reflects 34 on the price however the label reflects 30. I tried to change it at the Phoenix Plaza, however they only refunded me R60 The argument is that I did not produce a slip. While I do understand the policy , My argument is that is not my fault that Mr Price staff stuffed up when putting the incorrect size ticket on the jeans . Now I am out of pocket By R120, due to staff negligence. This is unacceptable customer service , not to mention . I first had to go back to Gateway and had to go to Phoenix Plaza.