Given damage goods and bad service

I bought a Blackberry 9720 phone last year September 2014. The showed me all its components but I when I got home it was not working properly. I sent it back within 7 days then I was given the new phone as they say. Surprisingly enough even that new phone was faulty and I sent it back to the store again 4 times. Woolworth told me they will send a phone to the factory I should come today(3-February-2015) to collect it. What **** me off and irritating is the fact that my daily work is highly dependent on the use of my cellphone and today I was told the childish thing ever by their employee Bongiwe Gasa that I should wait for new stock of which she doesn't have a clue when that stock will arrive while I saw new Blackberry 9720 on the display. Woolworth store is nonsense and their service is pathetic its been a month now without a phone.