Upgrade Went Wrong

Please note that I went for an upgrade at MTN store at Bayside mall in Cape Town store number SABC 0014 which is the store code, on the 26th of August 2020 - requesting that I want to upgrade to an IPhone XR or an IPhone SE but the consultant by the name of Shannon told me that they don’t have it anymore and it’s discontinued.They both suggested that him and the manager that I take a P40 Lite and that it is a better upgrade from the one that I am using. But when I got home the expectation of what I got were different from what they told me so Friday I took the phone back to the shop and they took it back. He then told me that he is going to cancel the upgrade and change the phone to what I want which is the IPhone 11. Friday the 28 I left the phone at the shop and they took it. Today I get a call that if I cancel the contract I am entitled to pay MTN R9400 if I want to do an early upgrade I should pay R9400 before it’s done. Or if I leave the contract The way it is I am stuck with the contract for 24 month and I have to pay it every month for 24 Months even though I don’t have the phone and I returned the phone to the shop and they took it. When I call the detention department to them it shows that I did do the upgrade and I took the phone and I am like I don’t have the phone with me........ please explain to me how am I stuck with a 24 Month contract with MTN deducting 500 a month for 24 months and I have no phone to show for it absolutely nothing to show for it. What the manger did to me and the attitude he gave me I literally broke down and cried at the store and what frustrate me the most is being stuck in a 24 month contract and I don’t have the phone.