SPECIAL OFFERS not correct when you get to the till at Checkers

BEWARE - SPECIAL OFFERS not correctly app**** when you get to the till at Checkers! Once again the special deal advertised on the shelf was not the same as on my till slip. I've started keep a running total in my head when shopping, this is how I know there has been a mistake when there is a discrepancy at the till. The 'mistake' pricing happens so often at Checkers that I now take a picture of the prices on the shelf to show cashier when they tell me I'm wrong about the price I saw on the shelf. Sadly rectifying their error is time consuming cos they send staff to the shelf to remove all the price tags for comparison, only after acknowledging that there was in fact an error on their side do you have to unpack your frozen goods for rescanning so staff can work out the difference to refund - spoiler, it was the same amount I had stated 10 mins earlier. My sharing this incident is not about the R30 mistake today but rather the principal of the matter - if you advertise a price then honour it at the till - this is not branch specific but all of them it seems. How many people notice if 20% of a discount offered is not app**** correctly? Honest mistakes or corporate strategy for maximising profit? Eish - come on, you must do better Checkers!!!