Change price of product that was already placed in my basket - Disgusting service

I placed 2 USN Diet whey Chocolate flavour milkshake tubs in my basket as they were on 30% discount for blue dot sale. When I added more products to my basket and checked out, Takealot changed the price back to R650. How can this be allowed. I complained and then had to rate the service. When I rated the service bad the consultant requested me to change my poor rating as in her opinion my query was resolved. Until I receive the price difference refunded back into my bank account, I cannot see the query as been resolved and will not change my rating of poor service received!