2 transactions to buy pie and coke

Hi, i walked into shell on new road to buy a pie and come, you have a special running on a pie and coke for r20odd, they tell me chees grillers and rusian rolls arnt part of the special(even tho they the same price, and the special says baked/premium/frozen pies?), so i daid i dont care, i will pay for ot, get to the till, ah no, we need to do 2 transactions, this is BS, and sounds like the owner of the shop doesnt want to run the special you giys have running, as i have bought this same combo at many other shellgarages, what ****es me offf it the fact they want to run 2 transactions