Dissatisfaction in customer service from Jet store Bloemplaza Bloemfontein.

I Bought a phone about 6 months ago at Jet Bloemplaza in Bloemfontein,after 5 months the phone screen became inactive without any damage on it. I returned the phone for repairs and it came back after 15 days. It was working perfectly fine by then,after 2 weeks the problem started again and I had to take it back again,which is a huge inconvenience because I'm using it for work purpose. They said I must wait for about 6 weeks while they take the phone back for repairs for the second time. I tried to explain to the manager that I can't wait for another 6 weeks as that puts my work at risk. The manager told me she can't do anything about that and that she can't risk her job. So my problem is that I'm a customer who's not happy with the service and treatment I got from Jet. I'm now sitting with a phone that doesn't work which is a huge inconvenience for me. I regret ever buying a phone from Jet. And I would honestly not recommend anyone to buy a phone from Jet again because of this experience. I need help to get my money back or a new phone.