Vodacom brushing off R28000 problem

3/4 months now ???. I have entered into a R1500 contract with vodacom an my new IPhone . Certain persons and areas can not hear me, my customers put phone down - complain they can not work like this - redial redial. Use another phone. Apple have replaced the phone 4 times to prove its not a Apple problem. Vodacom (Fazel the useless) is still getting back to me. I have a string of emails from my Vodashop requesting he get back to me - asking progress asking to fix problem. Apple have acknowledged and Vodacom admitted there is a problem but they do not know what to do. The answer - sooooo African, just ignore the problem.I have been paying for phone contract for months now and having a loan phone to use. R28000 phone an I must use a 10 year old loan phone - REALLY. Vodacom you a ***ard - and you renegaded on on our agreement, I pay you deliver, I can not use my phone. 4 dials a call people put down people complain - business phone ??