Online upgrade - Not receiving the same specials

I needed to upgrade my cellphone contract. Went to Canal Walk and wanted to upgrade my contract to the Huawei P8 @R399 per month however none of the stores has stock and none of them can confirm when they can get the stock either. If i upgrade my contract in store i get an external 1TB Harddrive + Additional 1GB of data per month for 3 months however if i do the upgrade online i don't?Tried talking to a call centre agent, but all they can tell me that online and in store deals are different. I need to understand why is the deals different? My contract rates are still exactly the same every month. When i go instore to upgrade my contract I have to spend money traveling to a store, I have to pay for parking, I have wait for an agent to assist me (If no one is available), sign a million documents to get the upgrade done, + pay R150 to activation ect. Where if i do it online i'm doing it at my convenience, there is no traveling costs, no parking tickets, no waiting in queue's no signing documents, and best of all no activation fees! Its convenient and safe. I am really unhappy that online specials are not the same and should be forced to go in store if i want a good deal!!!!