OUT OF PATIENCE

My new I phone 11 went in as there was a fault on the screen in July. I have been been told that they cannot fix it and will replace my phone. Every time i phone they say that they have no stock in the whole of South Africa of that specific phone. Do you really expect me to believe that you don't have any I phone 11s? I have been paying now for 4 months for a phone I don't even have. I have called 11 times this morning to the Cradlestone branch and there is no answer. Please I think I have been patient enough and I want this sorted today.