power bank. not received

i bought a cell phone J4 sumsung on contract at the cell c shop in Alberton mall. when i went to sign the contract i was told i will only receive the cell phone as they did not have the power bank in stock and sumsung company did not deliver their stock in full. i was told by the consultant that i will be called in a weeks time to come and collect the power bank, its been full 3 months now and i have not skipped a payment but yet not received what i am paying for on a monthly basis. i called the shop to speak to the manager as he was not there when i purchasing the phone, to ask about the power bank but the consultant refuse to let me speak to the manager and also refused to give his name, Finally he told me that his name is "KATLI" i asked the manager about the issue of not delivering he told me the same story of Sumsung not delivering enough stock they are also still waiting. i called the store to ask if they do have power banks for J4 Sumsung phone that i can buy and i was told yes they do have but when i asked if they have stock why as a customer who is paying every month i have not receive the power bank i was told "actually no the store do not have the power banks" the cell c shop has been giving me the run around about the power bank and i have run out of patience calling them and not receiving help. thank you..............