incorrect prices charge

This morning pick and pay verulam had a 7 to 10am sale we picked our stock up at 9am and continued shopping when we get to the till the prices are scanning incorrect we ask them what the matter they say the special ended at 10am we waited at the que for about 30min as the store was busy and they gave us no assistance with the matter, I am so furious w them as special items we choose we're marked and they charged us so much more once before in july my daughter was taken out of the troley and all management said was cameras we're not working this should be a family store and we support them continously I doubt they value our support