Alledged swabbing of coupons

Comfort 200ml stasoft has R10.00 discount coupons on it. At the paypoint did the cashier allegded that it was swabbed and supposed to be R8.00 discount coupons (that is actually on the bigger bottles). When telling her that it was R 10.00 did she not believe us and send the packer to go and double check. She came back and confirm that the R10.00 was actually correct. Did not get an apology from the cashier & will most certainly think again before I will go & shop there ever again. Embarassing to be made out being a thieve in front of other shoppers!