Bad attitude with regards to promotional pricing

Went to Shoprite on the 24-02-2016 around 18h15. Bought advertised County Fair Steaklets for R29-99 as shown for assorted 400g. Got to the till & got charged R37-99 & politely queried the amount with the cashier. Then the cashier asked another staff member to go & a have look & she brought the signage stating County Fair 400g assorted. The other supervisor wanted to assist but the store manager intervened & said the items were not on promotion & went to get the specials pamphlet. I told him the price I see is the price I pay as advertised & he left the cashier & I with the unresolved issue. He also closed the transaction without the groceries being charged but was packed in the bag & the cashier assisted other customer whilst I'm standing there. That manager gave me a bad attitude leaving me at the scene more than twice out of anger& what happened to managerial skills & decision making as for him to leave me more than twice at the cashier. After my procrastinated time the store was closed & only then he did the price adjustment accordingly & all of the above happened in front of the customers.