The store and repair centre lost my phone

Came in on Saturday afternoon at Maponya mall MTN (21 November 2015) to book in my phone for warranty assessment and I have received the service request number and all. Its Thursday and my phone still hasn't been to the repair centre. I called the repair centre yesterday and they told me that the phone hasn't got to them. Called Maponya mall again today (26 November) they say the phone has left the store but they cant say where it is at the moment. I called the repair centre again today (26 November 2015) they say the phone was collected on the 24th November from the store but they haven't received it. When I called MTN maponya mall today they don't know where my phone is and nothing has been updated on the system. <br> <br> I believe this is totally unacceptable. Someone needs to tell me where my phone is and make sure I get my phone back with the problem resolved. I cant even make payments from my bank because I only have a sim and no phone.