No answer as to when phone will be repaired

I've handed in my Sony Xperia Z3 compact twice now for the exact same problem and repair at Vodacom Customer services Menlyn. The problem I've experienced with the phone is that it simply would not pick up any wifi or connect, and it would freeze and go black at times, especially during calls and then I can't hang up etc.<br> The second time was on 10/01/2016 where I was told it would be fixed and ready for collection within two weeks. On 25/01/2016 I went back to the store after more than two weeks have went by, and still could get no response as to when my phone will be back from repairs, or even if it could or have been fixed. Then I was told I would definitely have my phone back before 29/01/2016. After hearing nothing from Vodacom I called today(28/01/2016) to hear if I can collect my phone tomorrow, as I was promised it would be done and ready for collection by Friday. Still I could get no answer as to when I will be able to get my phone back or whether or not it has been fixed or if they will be able to fix it. This means that I have now been without a phone for 18 days, and still can get no answer as to when my phone will be done and ready for collection???