Badly treated by staff

I bought a jean that was priced R249.00 After I paid I noticed that they charged me R299.00.i Went back to the lady who assisted me.And she told me there's nothing that she can do it's the System.She told me I either take it with that price(R299) or leave it.I was not happy with that response and she told me she's going to call the store Manager but to my surprise she came with another useless lady who told me that prices have gone up and they are not allowed to change anything on the system.I then asked to see the store manager and she told me I must go upstairs again to see the store Manager he/she is at the Customer service.I went there and found another lady at the Customer service,I explained my story and she took the till slip and the Jean to enquire and when she came back, she told me the assistant store Manager told her there's nothing that they can do is either I take that Jean or leave it.I decided to take it back.But I was not happy at all.I asked for that Assistant Manager as she told me the Store Manager is not avail ,To my surprise the assistant store Manager told me that stupid story and she said she doesn't want to loose her Job.Is either I take it or leave.