Poor service with no feedback on emails or calls

I sent MTN the request on the 2 Feb 2015 about device to be booked for repairs and had to chase them but I was told 4 days later that I filled the wrong forms so they sent me the correct ones which I filled and sent back.They only collected my device on the 9 Feb 2015 via courier but since then I don't get any feedback about the progress on my device.I sent them emails with the reference they sent but they don't reply even when I call I get cut off while holding for the customer service agent to assist me. I have been without a phone almost 2 weeks which is not good because I really need it as I use it for a lot of things.This is so disappointing to get such a poor service from one of the big mobile operators. I first went 30 Jan 2015 to their repair centre in Midrand where they couldn't find the device activation date which is also worrying because had I lost the phone and try claiming it was gonna be a problem because the Imei for the device isn't showing on their system.