contravening CPA

on the 10th April i went to Mr price cresta. they have a sale on some items & i took a pants that was marked down & the price on it was R10.00. when i got to the till & the pregnant lady scanned it it said R10.00. she then called her superior & showed her the price. i stood there for over 30 minutes them going back and forth. and eventually the supervisor says she can give it to me for R50.00 because the marked down price was R80.00. while doing their ups and downs they also insinuated that i changed the price. i told that pregnant cashier that when i got to her till that paper didnt look like it was tempered besides they have cameras in the store i would assume & i suggested they go & look those up. i was sooo humiliated by those lady & for a fault thats not mine. i told them am not taking the pants for R40.00 more than the price i saw on it. am taking this mater to the consumer board so they can decide.