REPAIRS to an iPhone 4

I have a contract with Vodacom (got three other lines on that same contract too and have been with them for many years). I am the principal member and when my upgrade was due earlier this year i received an iphone 4 (old model) after 3 months had problems with the phone. I took it to waterfront shop and from there they sent it to the workshop in green point, After one week i got the phone back and after a month experienced the same problem and twice after that too. I am not happy and have been inconvenienced, and had to take the time to go back and forth every time. They have now sent the phone to JNB for repairs. Job no. ***8, I followed up on the status thereof yesterday and they said it could take another week!!! I am not happy with the service and the handset and insist on getting a new one.