Phone out of order

Since the day I received the blackberry z10 from mobiwarehouse it has been faulty, now the phone won't switch on completely , I called Price Jacobs yesterday, explained that I use the line for business , he said I must take my phone to any MTN shop, as the supplier is AVTEL, He gave me a form , saying I should go to any MTN store with that form, went to MTN, the couldn't recognise the IMEI Cumber , and I called Mobi, Prince was on lunch at 1:30, they said he will come back to me . It is no 16:37 , NO CALL form Prince , I had told them previously that they should keep their phone , which is dysfunctional , now I'm at a point that I will have to go the consumer protection and speak out rout ... I'm SICK of MOBIWAREHOUSE and their TERRIBLE service , this is unacceptable, I'm in Capetown, stuck with NO phone , and business must stand still because of incompetence from MOBIWAREHOUSE... I'm livid to say the least