rude staff,bad service,no response and dont care attitude

Hi..i bought a phone (grand prime) from jet store lenasia trade route mall in August, cash,i also took out insurance on the phone but put it on my account.less then 3 months the front camera stopped working.I took it back to jet they sent it to Vodacom and Vodacom sent the phone back saying the guarantee fell because the phone is water damaged and the screen was cracked and that i havent paid the insurance.(the phone was never in water,and in working condition,besides the camera when i sent it in and it had a screen guard which was cracked)untill now they have my phone.i keep phoning the store to ask for the manager to find out why it's taking so long but the guy who helped me the day i bought the phone turns out to be the manager(well thats what a jet employee told me) .every time i get rude responses from him.I've also been to the store many times and they keep giving me different stories and that they would credit the account so the insurance goes off,but nothing has been done so far . I also called them again today and they promised to get back to me which they havent.they also told me it takes 21 working days maximum for a phone to get fixed.and its been months since!!