NO FEEDBACK OR CUSTOMER SERVICE

I bought a Nokia Lumia 535 handset from Altech Eastgate on the 07.03.15 . I had the phone for a few weeks when the screen suddenly went blank , the phone is still working , but no screen . I returned the handset to the Eastgate branch in the second week of April , and informed them that I wanted a new handset , as I had only had the phone for just over a month , and I had googled the problem , which is apparently a factory fault . I was informed that they are only the retailer , so the phone would have to be assessed . I explained that it was a work phone , so I needed it back urgently . After hearing no feedback from Eastgate for over a week , and no answer to my numerous phone calls , I went back to the branch , where I received zero customer service . I was given a number to follow up on the repair eventually , and discovered that the repairs department knew nothing of my phone . I returned to Eastgate to discover that the phone was still in their store ! I have called the supposed customer service number numerous times , with no satisfactory reply , apart from my phone is with a technician . The last updated info being dated the 23rd April . It is now the 5th May . FURIOUS !