poor customer service

I saw a Goldair heater on the shelf for R399 but when we got to the till points it scanned a different amount.I then asked the Cashier to call the superviser,she came and heard the query then went to the electrical department.Few minutes later she came back with the department manager,he didn't even want to hear our side of story he just said its impossible for this heater to be this price.I then asked whose fault ist that the pricing is not right,he then said he doesnt know. I then went to the GM,he was on the phone he then refered me to the same supervisor that the cashier asked for assistance the first time and she didnt assist.The GM got off the phone instead of coming to assist he just stood there and did nothing,worse part of it all is that the till was closed for over 20 Min and it was facing where he was sittting,I paid R599 for the heater instead of R399,I was with my cousin and the intention was to buy two heaters but because of the service we got there,we ended up buying only one.Incorrect pricing is an incoviniece to the customer and I consider that as poor customer service,