Phone issue

Hi 1st of March I went to buy a phone at jet I asked someone who was helping if the phone was locked he told me it was duel. I bought the phone and went home only to find out when I get at home the phone was not dual. I returned to the store the next day. I was help by the a different person who also told me the phone is a dual phone. I then asked if they could exchange for me to the me the one that is dual bcz the one they gave wasn't what I bought. They went to search and did not find it. Bcz I was late to work I went n came back during my lunch period.... then I was now helped buy the guy named Vusi which he was rude to me that he told me that he will not exchange or refund. I asked for manager he told me he was which he ****. The next day I went back to the shop again I asked for the manager which I was speaking to he told me the manager was on lunch ...with an attitude... m not happy with service I recieved from jet ... still haven't got any help . I hear the manager is bragging about he wont help me