STILL NOT REPAIRED AFTER SENDING BACK TWICE

I sent my new iPhone (under 2 months old at that stage) in for repairs as there was a problem with the speaker. It came back and it still had the same problem. I phoned the repair centre and while I was on the phone to them the same thing happened. I was told to take it back which I did. It came back with a note saying there is no problem. I again phoned and it did the same thing again. I now have to have the inconvenience of having to drive to Midrand which is 30km away to try get it repaired. I told them that I wanted a new phone but that fell on deaf ears. I have tried phoning and speaking to management, but keep getting blocked by the consultants. I had a previous iPhone through the istore which had the same problem. After trying to repair it the 1st time and not succeeding, they gave me a new phone without hesitation. hopefully this compliant does not get ignored and a get a call back from somebody in a senor position.